It came up OK right from the start, I was thinking of plugging it in using a long extension cord from the next room, with a fire extinguisher handy

I put a couple of  pics of it mounted in its tweed cab in the "Pics of completed Overtones"  Thread
Not sure any more pics of internals are required but,

I guess you're referring to the big brown ones on the main board. I looked at your build pics, they're certainly different, much larger for sure. According to the layout they should be .1uf, maybe a higher voltage rating.
There seem to be polarization marks on them, but they're not electrolytics. I recall a few weeks back I was reading a thread on I think, the ampgarage site concerning an amp builder who was  testing some of his allegedly non-polarized caps, finding a consistent difference in performance depending on polarity. Maybe Nik has picked up on this and started doing the same.

The outer foil is marked because it can be used as a shield against electric field coupling into the capacitor.
It looks like this: plate voltage-->>cap(outer foil-->other side;inner foil)-->>to next gain stage.

When done the right way your amp can be considerably more quiet.

For further info on this subject visit: http://www.aikenamps.com/OutsideFoil.htm