Hi Bernard, Hi Bob
I had this same conversation with a very good local machine shop last year
FWIW this was the conclusion:
There are plenty of liners around and they're cheap - maybe $100? They can bore your barrel to size and press in a new liner and trim the top and bottom etc. Then, if you have a piston - or dimensions of the one you want to use - they will use their experience to decide on a clearance and machine the liner internally (bore it) to make it circular and of the right size
This is where it gets potentially trickier. Original Listers have a really clever, chrome-coated bore designed to hold a film of oil and resist wear - that "hard" bore is designed to work in combination with "soft" piston rings - I think I have that right and others, more knowledgeable, will correct me if I dont
Your new bore will be of "soft" cast iron and will require "hard" (perhaps chromed?) piston rings - and that may require machining work to the piston - depending on what is available?
That is my understanding
So a "rebore" is only half the question, I believe
"do your homework" is probably the advice
FWIW the finished job of re-sleeving, trimming and boring to suit a piston dimension and then "facing" the barrel square top and bottom was $390
I just bought new, Indian, barrel for the same price
Cheers, Mike