You're right, there is one ASIC but I can find it on ebay.
Actually the main problem is the crystal, its frequency is 13.10669MHz, I can't find one.
I'd love to buy another 2465B but they are difficult to find in Europe, and if I buy an oscilloscope from the USA I need to add about 250 USD for shipping and tax...
That's why I'm looking for cheaper (and lighter !) boards :)