So, the risk of failure caused by the HT-40 leaky capacitors is moderate.
On the
other hand, if I would replace the leaky capacitors, I would have the
certainty
(and not just the risk) of spoiling the originality of the radio.

I am of the opinion the originality of the radio has been compromised when
the caps (and other parts) go bad and do not perform up to original
engineering intent. Like a Fender Stratocaster or Les Paul with an old leaky
bubble bee cap that sounds nice, mellow, fuzzy...(insert description). It
did not sound that way from the factory either. This old bubble bee is a
whole new sound. Pleasing and desirable, perhaps, but not original.

And there is the engineering part of me that says if it is not operating
with in spec it is broke.

But this is a whole other philosophical discussion.

Just my opinion,
Paul P.