Hi stepdog, welcome from Scotland.
Thankfully, the technology has moved on in the last 30/40 years.
The parts you require are
easily available from many vendors.
You're obviously a very patient man!
I've also heard good things about 'Posies' springs and I agree with Waldo.
JMO as well, but I prefer the under floor brake set-up for a cleaner firewall.
Obviously the final decision is yours.
BTW How about some pics?
Good luck.
Jock
