As a new owner of a 1963 Hassleblad 550C what B/W filter brand(s) do you reccomend? Should I go after 'blad bayonet filters, size B60, or buy an adapter of 62mm or 67mm or another size and purchase other branded filters?

I also use a 4 x 5 Speed graphic, if an adapter is a factor for commonality.

Thanks.