ajs restoration

Hopefully a few may be able to shed a bit of light on the topic, basically we have a 1959 350 ajs with crankpin problems, it hasnt been started for a while either, and i understand that the crankpin is a bit of a common fault.
Can anyone recommend somewhere that i can buy a replacement, and also would it be a difficult job to replace?
Thanks for any advice wes

try the ajs-matchless owners club on the net or old bike mart, shepton mallet in october

http://www.ajs-matchless.com/

Try here. They have a extensive online shop for all AMC machines.