(04-12-2021, 11:02 PM)Martin Prior Wrote: Francis - Yes, the tracks are screwed through the leathercloth. We fit them with a bead of sealant under the track. The bolts that you mention sound like something that shouldn't be there. Can you post a photo?
Martin et al,
I beg to differ on this one, having researched the originality of this feature extensively in the seventies and eighties when rebuilding several Ruby and late ('34) Box type cars. In those days we had the resource of country scrap yards, still with original cars to forensically examine.....
The roofs were assembled by the Pytchley Autocar Co. Ltd. and presumably shipped to Austin as a sub-assembly. As such, they were self contained, merely needing to be placed on the production line with sealer into the body opening, located with the four 2BA or 5/32 BSW bolts (they
are supposed to be there) and then screwed from inside the car, through the body and up, into the frame. Production engineers would not have tolerated assembling the roof bit-by-bit on the production line because it would have taken too much precious time.
The sliding ("H") frame was attached with rivets, through the steel edging after the roof was covered in fabric. I believe soft alloy rivets were used for this purpose.
As such, when restoring, the whole roof should be able to be built up off the car, then "dropped in" to the hole in the bodywork with sealer and secured from the underside only. The sealer needs to be able to flow around the section, some caravan mastics are probably best to use these days. Obviously today, the frame would have be built to suit the opening in the body but the whole sub-assembly should be fitted in one piece, sliding panel as well.
This is probably controversial because most restorers will have screwed the frame on from the outside but it's not how it was done originally I can assure you.