Grey smoke from a KEL84 - Help!

[misterc6]

This morning I decided to try a different set of 4 EL84s in my KEL84. Lovely music for about 1 minute then a crack and the dreaded grey smoke.

I have looked inside and it's clear that R29 and R31 (100R 0.5W) are badly burnt, C15 (100u/35v) is bulging at the top, and I suspect that C13 has also suffered some damage. I now think that R27, and possibly R25 (270R 1W) are also damaged.

Questions:
Is that likely to be the extent of the damage?
Will the Output transformer be damaged and how can I test this?
When I've replaced the components what should I check before refitting a known good set of EL84s?

I have replacements for R29 and R31, but not R27 and R25, nor the capacitors. Is anyone able to help me with some replacements? I will of course pay for these and the postage.

TIA,
Malcolm