Have done a quick search and couldn't find the info elsewhere.

Is there a good site that'll tell me what replacement pots to get for my Marshal JCM900 4101, as in what rating I would need for each one?

I am looking at refurbishing this old beast with a new set of pots and have a friend who is very good with electronics. The pots have got very "scratchy" and I have been looking on Watford Valves pages at the various Pots they do, but would need to know the K ratings so I get correct replacements. I've also had a look here http://www.drtube.com/marshall.htm#JCM900 at the wiring diagrams, but I'm not that good with electronics myself so don't know how to interpret the values of the different pots and wondered if there was a technical website somewhere that would have the info.

Following this thread https://www.ultimate-guitar.com/forum/showthread.php?t=784752&highlight=JCM900+valves+metal I am looking to get some JJ-Tesla EL34L's and the Hi Gain ECC83's to go in it and then a Tube Screamer to give me something near-metal until I can save up the readies for an Engl Powerball II and cab.
Ibanez MTM2, Bugera 6262 2x12 Combo
The values are written on the back of the pots. Just have a look.
Gilchrist custom
Yamaha SBG500
Randall RM100 & RM20
Marshall JTM45 clone
Marshall JCM900 4102 (modded)
Marshall 18W clone
Fender 5F1 Champ clone
Atomic Amplifire
Marshall 1960A
Boss GT-100

Cathbard Amplification
My band
Heh! I knew it would be simple! Cheers
Ibanez MTM2, Bugera 6262 2x12 Combo