[morzh]

After I have soldered in the interstage transformers, I covered them with fishpaper. Just in case, it seems they did not touch anything.
   

Then I closed it and eventually used a stiff toothbrush with some extra Goop on the embossed letters and  the creases around the tubes' sockets.
The result is pretty decent.

   
   

Now to rebuilding the 0.2uF decoupling cap.
   

It shows 0.9uF on my DMM and 0.5 to 0.9uF on my Stanford Research LCR analyzer, depending on the measuring frequency.
   


Thing is, I forgot how I did lifting the can's bottom before. I know I removed solder. But this one is stubborn.
I will consult my AK82 thread. Though I doubt I put the exact technique there. Will have to figure it out all over again.
Short of using a can opener.

PS. Well...I was of a worse opinion of myself. I did put the exact technique in the thread. And it is exact same as I've been doing now. Heat the can and shake off teh solder.
Except the solder is not shaking off. Maybe gotta get it hottel. Maybe the tin is thicker.
Oh well, I'll get it somehow.