Any decent cylinder sleeving outfit should be able to make 1, I'm guess the fact that more places are able to do nicasiling/electrocoating now may have meant less people wanting sleeves done
Thanks for the advise on removing the sleeve ShakeyCZ, had 1 of the sidepiper barrels apart today hoping to fit the sleeve out of my normal barrel but ended up having to reassemble it due to sleeve diameters being quite different
For anyone thinking about replacing a sleeve I'd say give it a go, it's surprisingly easy