Thanks Greg. Just ordered the caps.It's typical 70's and 80's Marshall stuff with 3 dual cap cans at 50uf\50uf-500vdc, and a pair of axial 10 uF capacitors.
I like the ARS caps. They look identical to the old LCR caps and perform solid. Here is ARS's Ebay site:
You still will need a pair of the 10 uF - 150 V caps (Sprague Atom). You can get everything at Valvestorm, including the 1K/5watt power resistors for the screens if you choose to replace those too.
Here's the 2 page schematic:
