Back when I was planning my mini roadster, internal hinges were on the menu. Yes, I DO know exactly what it takes to fit Rover doors to a Morris shell....... and in simple terms, you replace everything between the front and rear seams.
What exactly do I mean by everything????
Okay, here is what you do.
Remove one of your door seals..... all of it. Can you see that lip that the seal was pressed onto?? It is made up of 2 (and sometimes 3) layers of steel.
What you need to do is:
* seperate those 2 or 3 layers around the door
* seperate the 2 layers around the side window
* seperate the front and rear seams
* seperate the lip that runs along the bottom of the door between the bottom of the wheel arches
* seperate the roof gutter layers along the sides.....
.... and then pull the whole side AND wing panel away from the rest of the car, like so.
**** ^^^ please note that the wing panel should still be attatched, you need to replace it with the new one.***
Now you take the same side panel that was salvaged from a Rover (or UK Leyland) and graft it onto your car. You will replace the hinge mount locations, door frame, b-pillar door catch, side window frame, etc etc...... everything on the outside of your door seal and side window seal.
This is the easiest "proper" way. Its just a matter of keeping everything square before it's welded back together. Your car will probably sag when the sides are removed, making reassembly a fair bit harder
Not impossible, but pretty f**kn close to it.
Oh, by the way...... the frame and doors I WAS going to use for my roadster are still at Brickworx, ready to go. BUT I think these sides were cut off just behind the door frame - you should be able to graft it to your existing rear side panels...... Give him a call and see if he'll sell em to ya (8297-9494)