I also have a HP-35 with manual, purchase receipt,
hard case, and
power supply. It doesn't work with the power supply as is, but I
don't know if the power supply works. Available for shipping costs.
_Any_ LED-display HP calculator (and for that matter early LCD models,
the HP71 and earlier) are _always_ worth something, no matter what the
condition is (OK, not if they'rve been run over by a steam roller ;-)).
There are plenty of people who collect and repair such machines and can
use them for spare parts, etc.
If you want to have a go are repairing the HP35, I can tell you what the
testpoints are and what you should see at each one.
-tony