[D Cassidy]

Hello Aidan.
Thank you for taking time to read my post and make your comments.
Everyone is different and will approach obstacles differently, moving onto a later set with a live chassis may sound like a sensible decision but it too has its hazards, the requirement of an isolating transformer, the greater risk of having asbestos around the mains dropper could add alarm bells to the young lads Dad.
Mains Derived EHT, needn't be an issue so long as the EHT caps are in place or even replaced with better modern types, like I say all initial work should be done cold and improvements made for safety.
The B16 Pye is a simple circuit, slightly awkward granted but nothing really that will catch you out. In fact the mains transformer could be the biggest problem with an open circuit EHT winding.
I think we need to leave it to the young lad to make his mind up after weighing up the replies. I do though think he should keep the set if he decides to restore a later set. He would regret it if he sold it on or scrapped it, remember it is his property to do whatever he wishes.