You are right Neil, it is down to skill and tools . I can't cut or drill a straight whole or cut a straight line to save my life but thanks to a piller drill and a good sliding chop saw I can do it like a pro, and I am not worried about taking an angle grinder to the top plate although I cut wide then take my time to gently grind down to size, but as you say a fettled 401 with arm and plinth would be a better sound and cheaper . However a fully modded Lenco don with care will give a 301,401, and a 124 a very hard run for the money. Saying that. ....its all down to what your ears tell you, mine tell me a well modded Lenco is a very hard act to deal with.
Regards steve