As an update on progress, i've finished repairing the frame including the internal brackets and strengteners that had rotted off.
I then turned my attention to the top section of the door skin that remained, I cut out the rotten section on the front corner.
I then made a repair section and then welded it in.
Next I cleaned up and painted the inside of the frame ready to fit the skin.
The skin was fitted and welded a bit at a time.
The all important drain holes were cut into the skin using the nearside door as a template for position and shape. I have checked the original door bottom again and it definitely didn't have any drainage holes in it from new which is probably why it has rotted so badly.
Interestingly the inside was a different colour primer but its only been painted twice, once in the original gold of the car and once in the horrible flaking off beige that it is now. I did previously notice that the rear door on this side was blue inside which suggests its been changed so it may have been that the car was damaged at some point (there is a dent along the front wing as well that suggests its hit a bollard and put a crease in it).
I wonder if they couldn't get a second hand front door so bought a new one and it was a reject/faulty or was just made wrong.
Finally with some filler work.
I've started on the other side but I will move back to the thread for the car to report progress on that one.
A few things I have learnt from repairing doors on MK2 Jags historically and now (thanks to all those who posted above):
1. Don't use any form of sealant between the skin and the frame, it sounds a really good idea but if you use the wrong type and then weld through it the sealant turns acidic and starts to rot through the door skin.
2. Don't seam weld a part skin on, unless you are really careful/lucky controlling the heat distortion is next to impossible for someone with my skill level.
3. When joining a part skin try and do it on the flat section, joining it on the curve causes a lot of problems (this will depend on the quality of the panel but MK2 jag skins tend to be not very well formed at the top.
4. Make sure to weld the skin to the frame to stop it moving, spotwelding through works well as original. If you don't the skin will move on the frame and crack the paint on the back which then leads to rust.
5. A 4 year old can make a really good job of painting the inside of a door frame but don't let them get any paint on them as its a nightmare to get off a screaming child!
