If the evap equipment is removed then you would need to revert to a vented tank. Could be achieved by changing the fuel cap.
The MOT testers manual section 7.2 doesn't appear to require the tester to confirm that the evaps system is operational. It does require the cap to be in good shape and that there are no leaks in the fuel system and as follows
'Check fuel tank cap /filler neck sealing device
for presence, positive fit and condition of sealing
washer and flange.'
So I don't know if an MOT examiner would have any grounds to fail a vehicle with a vented tank.
However the vehicle would no longer conform with construction and use regulations, and may be considered unsafe if the vehicle should overturn. That would be a golden opportunity for an insurance company to refuse to pay out. Also I guess there is a possibility of failing a roadside emissions check.
Best to start off with an old Morgan that predates all this emissions stuff, or ensure you can pass inspection if you have a more modern Morgan.
Sadly (or fortunately) we can't get away with what was done back in the 60's. A recovery garage I did some part time work for ran a fairly rotten zodiac for local taxi service on trade plates. Only picked up old ladies to take them to church on sundays, honest !
Mike