1Ж42А. As a mixer/Frequency changer????

[Mike Watterson]

Oh, and my sympathy on the battery accident.
At least they aren't totally unobtainable, or madly expensive like an 1L6. I've accidentally zapped filaments and sometimes transistors with power misapplied.

I'm tempted to 10mA current limiters and diode clamps if experimenting with something irreplaceable.