As usual, I read the GD documentation and loads of blogs before doing anything, and the thing that stuck with me was a couple of measurements, those being 415 mm from the outer edges of the stanchions and 505 mm. This being the measurement between the centre points of the spindles. To me, the 505 mm value was sacrosanct, the other 415 mm measurement I had room to wiggle things about a bit.

 All marked up ready to go

 

As with everything, I first made my own measurements to verify where to drill the two spindle holes, and I cross checked their position from different reference points on the car. And as you can see I came up with a variety of "correct" positions... Not good!!! So I decided to use the centre point on the scuttle as my "ground zero." However, I noticed there was a 3 mm discrepancy with this and centre point of the windscreen. Also, as the windscreen is a flush-fit to the bodywork at both sides i.e. the stanchion legs are butt-tight to the bodywork, no room for manoeuvre there. So in reality my centre point was defined for me, and [in this case] a 3 mm offset from dead centre could be down to anything and isn't going to be noticed by anyone [except me.]

 The three arrows indicate the correct 'relative' positions.

 

Wiper Spindles: I centre measured and marked a point 25.25 cm from the centre-point of the windscreen. Then I measured where to put the rubber gasket (5 mm from the screen rubber) and taped it in place. I then marked where the elliptical hole was to be drilled and taped the chrome spindle cover to the top of it. This to provide me with a correctly angled drill-line.

 First, I made a 3 mm pilot hole, then used successively bigger drills up to the diameter that was just below the diameter of the spindle. I then removed the spindle cover and gasket and used the Dremel rotary sander to finish off and clean up the hole. Test fitted the spindle and chrome cover and... Not good!!! 

I had no thread showing for the retainer nut to catch onto. It was as if the mechanism was too short... Tea and think time!

Further investigation gleaned the mechanism was designed for a thin metal skinned scuttle. The GRP on my scuttle being ~4-5 mm thick, so the aluminium angled spacer needed shortening to produce the desired approx' one thread clearance above the nut. 

I shortened the spacers using the Dremel and the metal cutting disc and test fitted the spindles, and I was quite pleased with the result. However, I noticed, looking from the underside, the angled spacers were not sitting flush to the scuttle. Checked the spacer angles and they were correct, so it had to be something else causing them not to sit properly. The problem was the shape of the scuttle. It being, a.) not a flat surface (i.e. curved): and b.) Inherently lumpy and bumpy. The curvature was not an issue, the lumpiness though was the problem as the high spots preventing the spacer tube to sit properly. So I lightly sanded the GRP to make it flatter and used some gelcoat to create a mould for the spacers to sit snugly on. Didn't' need to make much but it was very fiddly gelcoating upside down. No major issues but I knew I only had about 8 minutes before the gelcoat would "go-off,' And in this theme I didn't fanny around and I put the spindle mechanisms back in place and tightened them up quite quickly.

Dremel Strikes again... Excellent piece of kit!

 

One Done... One to go

 

Not a good sitting

 

Much better... Now for a drop of gelcoat to make them sit perfectly  

 

Also, having some spare still-wet gelcoat, I spread some around the outside of the spacer tubes and on the body thereby sealing the two together. Twenty minutes later the mixture was still very tacky and hadn't gone off. This concerned me... I had used the same mix ratio as I usually do, but what was different was the ambient temperature. It was a lot colder. A gentle blast with the heat gun later cured the issue and it set hard. The spacers now sit flush on the scuttle underside and the wiper mechanisms are very - very secure.

Note... the mechanisms did not stick to the inside of the tubes because: a.) I was careful not to get wet gelcoat everywhere, b.) I could unscrew and take them out to clean the inside of the spacer tubes without dislodging the tube position, and, c.) I smeared them with wax (just in case.)  

Much Better, and a good strong fix.

   

Am happy with this


Wiper Motor: Fitted the wiper motor to the steering rack and bent the middle bundy tube to the same shape as the scuttle... Problem though!!! The middle bundy tube was 2 cm too long, and, as it had pre-flared ends, I obviously thought I had drilled the holes in the wrong positions. But, as the spindle spacing was correct [505 mm] and the distance from the outer stanchion edges was near-as-dam-it [415 mm,] the tube must be the wrong length. But I need to verify this before doing anything else.

Talked to Andy at GD who informed me that he did have a batch of tubes that were not the correct size and I probably had one of these. Panic over, tube cut to the correct length and re-flared using the end of a pointy-nosed pliers and centre punch... I don't have, and I have no intention of buying a flaring kit for a one-time event.

Flaring tool (my centre punch) and the final fitting.... That's going nowhere!

 

Fitted everything in place, and I have to admit it looks pretty neat. Not tightened anything up yet as I have some more drilling to do in the area so it'll all have to come out again soon. I do intend to change the nuts on the mechanisms and motor to nyloc ones though.

I will determine if I need to reverse the gearing at a later date. No need to do worry about that now. I also will have to bend the wiper arms to make them look and sit better on the screen, but that too can wait.