If I am not mistaken, Block 12344 contains a notable bi-twin chain. The origin is 107 digits long and it is a chain of 3 links (i.e. 8 primes). It is not a world record, but would be 4th on the list of chains of 3 links. I was the miner of this block and would be willing to demonstrate ownership of the coins.
You can verify you own an address with the signmessage command:
primecoind signmessage addresshere "Koooooj owns this address"
and posting the address, message, and signature.
(I think you could run that in the debug console too, just omit the primecoind part at the start. Or is there just a UI to this feature? I'm not using the QT client.)