[G6Tanuki]

It looks clean - but the yellowish wiring is rubber-covered and is really a crumbly-nasty 1940s liability, which needs replacing throughout before you try to power it up.

There will also be loads of leaky paper decoupling capacitors, and a few equally-flaky electrolytics - that after 70 years wlll need replacing.

Then - any resistors which are of the "ceramic bodied with colour-bands on the ceramic" and a sort-of flowerpot-coloured 'stuffing' at the ends - they're well-known to going way-off-spec after a few decades, and should be replace-on-sight.

A CR100 with the aged capacitors/resistors replaced by modern within-spec parts can be 'intriguing'.

Trying to use one with loads of drifted, past-their-time parts is a frustrating folly.