MK IV Door hinge plates

I’ve just in the process of removing the doors on my 1948 MK IV (1 1/2 litre) and found that some of the screws holding the brackets to the door pillars have been previously stripped or snapped. I will need to drill these out and re-tap the holes. However, it would be easier if I can remove the rear adjustable plates - but how are they removed from the centre door post and rear body panel ? Any suggestions or experience please. Thanks

The B pillar ones might need to have a hole for access cut in the inside face of the pillar . The C pillar ones may be more eccessable.
Hoever, if some of the four threads in each are still useable you could make a plate with say three holes and use this to clamp the retaining plate while you drill and tap the hole, one at a time.
If the thread is unsalvageable BSF recoil kits are available.
Use nickel anti sieze when putting the new screws in

Thanks. I will have a go with the plates in place as you suggest, as I don’t want to cut them out if possible. I guess the plates were put in when the pillars were made and before the they were welded to the bodywork shell. Looks like a design oversight!! I use anti-seize on most bolts being reassembled, although I doubt if I will be around in another 70 years when the car might want a full rebuild again and for them to be unscrewed for a second time.