From my experience I would strongly suggest getting your own set of manuals and notes. Many of the Gipsy 'experts' are very far from that.
I'm sure there is a hard core of people who really do 'know'. All you have to do is find them - but you'll only know they are not right when things go wrong and you're faced with yet another bill.
But there are dozens who do not know what they are talking about - not that it stops them doing work, flogging parts and offering completely erroneous advice.
Gipsy parts are nearly all ex-military these days and this offers many people a serious oppertunity to make a lot of money by selling parts which were effectively sold as scrap with a shiny new piece of paper.
This makes part numbers incredibly important as any idea of real traceablity for 50 year old spares is pretty laughable. Best of luck in sorting things out.