Coupe window frames comprise brass channels held together with dinky steel corner brackets secured by #6-40-UNF screws. One of the brackets had broken, some of the screws had broken off in the brackets and some of the tapped holes in the brackets had stripped.

With the window frames disassembled the broken corner bracket was pieced together on a jig and rewelded, and the broken screws drilled out and extracted. Replacement UNF screws were not readily available (in UK) but 4BA raised head countersunk screws in stainless are, and have the advantage of being slightly larger in diameter so a 4BA tap gives a nice clean thread. 4BA is 0.142" diameter with 38.5 tpi and #6-40-UNF is 0.138" diameter. All the 6:40 screws were replaced with 4BA.

The forward bracket for the lower quarter light fixing to the top of the door was also broken. The broken rivets were drilled out and replaced with 2BA countersunk screws tapped into the bracket.

OE fixings for the nose piece at the front and the pyramid at the rear of the door are 4-48 and these can be replaced by 6BA which are interchangeable and available as slotted raised head countersunk stainless screws in the UK.

All the glass was pitted with grinder sparks (not by me!) and had to be replaced. The quarter light seal sold by Moss is 1.5mm thick with a consistency more like mastic than rubber. It is far too thick and shreds when the glass is pushed in. When formed into a channel over the edge of the glass there is no way the glass will enter the frame and I feared the frame would bend.

The solution was to use 0.9mm thick neoprene pond liner which was stuck to the glass with mastic and when dry pushed into a bed of mastic in the channel of the frame. A mess of mastic which cleaned up well with the glass fully into the frame and securely fixed.

On 12/29/2018, Mark Wellard wrote: "The SPL lists the nyloc nut for the ¼ vent swivel as ¼” UNF (LNZ204). This is what Anglo parts offers as a replacement. However, the thread on my car is ¼” BSF (26 TPI). The hollow nut from an SU float bowl turns on freely". After some public inquiry, we have multiple verificaton that this is indeed 1/4-26-BSF thread, not 1/4-28-UNF. The BMC part number for this nut would be 2K3975.

None of the UK suppliers has the inner drop glass seal, a strip of steel with a furry edge which fits under the door capping, although Clarke supplies them in the USA. The picture below shows what is sold as the outer seal (AFH4455) fixed with minuscule countersunk screws onto the inside edge of the door capping, also countersunk.

The original AFH4455 outer seal looks like an invitation for water to enter the door and is held in place by 5 S clips and retained by the finisher strip. I bought MGB seals AHH6348&9 which were cut down but there was no way that these could be fitted. So it was back to AFH4455 and home made S clips shown in the middle picture and sketch.

There is no gasket or joint between the bottom of the quarter light frame and the top of the door. I have sealed this area with mastic applied between tape guides so that it is hidden by the finisher strip. The end of the mastic is just visible in the last picture.

If anyone knows of a way to fix a rubber wiper seal in place of the AFH4455 I would be pleased to have details.