I have recently acquired a 60's Ashley 1172 body.
The Ashley's were designed to fit a Ford Popular sit-up-and-beg style car but a Triumph Herald is a close enough match so I started with this Triumph Vitesse.
Cut it SAMMIO style.
Then placed the Ashley body over the top.
It fitted quite well and was a little short around the bulkhead area, but it was abundantly clear the bonnet would not cover the engine unless I made a bulge the size of a up-turned wheel-barrow placed on top the bonnet.
I then turned my attention to a Triumph Herald 13/60 rolling chassis.
I thought the smaller engine would give more room under the bonnet so it was also chopped SAMMIO style and the body placed over it.
Again a reasonable fit but the engine was still causing problems under the bonnet. I also noticed the brake and clutch master cylinder were sitting too high to fit under the bonnet.
IMHO the solution is to build a bespoke steel cage frame to support the body and to move the engine back to give a little extra room.