I know nothing of tube rolling, etc.... But for those interested, Farnell carry stock of valves from a company called "Chelmer Valve". They have: ECC83 @ £5.90 EL84 @ £8.00 EL34 @ £12.15 KT88 @ £30.27 6L6GC @ £11.80 6L6WGC/5881 @ £18.83 GZ34 @ £19.16 Not sure how these prices stack up, but hope they're of interest/use to someone.