The person who suggested SSL 3.0 is (was) not sure what device they had.
See:
https://www.mobileread.com/forums/sho...54&postcount=8
(PS: it was SSLv2 that was taken out of service - nearly a decade ago.)
The rest of that thread seems to agree - we just need to install a current trusted certificate store.
Tomorrow, time permitting, I will check those other links (and do an ascii dump of the certificates - in particular, the root certificate - which should be on the Kindle).
We can probably generate the required root certificate collection - but the K2/DX/DXG will have to be jail broken to install it (same firmware build on all three devices, the DX(G) are just large screen K2 models).