H. Neary wrote:
Is there a simple way of fitting a door to an arched internal walkway?

Yes, install a normal 'square' door frame and door, and block off the half
round bit above with whatever material you like, wood, plasterboard etc



I could probably use off the shelf items for the doors and straight
bits, but how would the frame be fitted to the arch? Is there a wood
that can be shaped to accomodate the door then soaked or steamed to
get it to follow the contour?

This would probably cost more and take longer than WW2