Cracking partial hex seed for Ethreum Presale

Hello and thank you to any prospective helpers.  Apologies if this is obvious, but I may have missed something in the mask documentation or have been looking in the wrong place.

I have been unable to decrypt an ethereum presale wallet despite thinking I used a familiar password ending in a special character.

I intend to attack via a different path.

I have 59 of 64 hex bytes that I think are a backup of the seed made during purchase.  Probably in the correct order or in one of a small number of permutations of order (split across multiple post-it notes as an emergency backup.)

I suspect the additional bytes belong on the end but I would like to try all possibilities.

I am trying to crack a Keccak-256 hash of this hex(number) + 0x02 (hexadecimal two.)

Is there are an efficient way to crack this?

Thanks again for reading