how to evaluate if this (or any) bitcoin public key / private key combination is valid?
1) A Bitcoin address is between 25 and 34 characters long

2) the address always starts with a 1 (in this case)

3) an address can contain all alphanumeric characters, with the exceptions of 0, O, I, and l.

(ref: https://thomas.vanhoutte.be/tools/validate-bitcoin-address.php)

Now here comes the hard part: The last four bytes of the address are the first four bytes of Sha256(Sha256(2,3,4...21th bytes of the address))

More info: https://bitcoin.stackexchange.com/a/50879/38618