I just joined this forum..looking for help. Just took ownership of a ‘77 38 Californian w/ twin Perkins..my first self-appointed duty is to replace Zincs because they haven’t been done in a couple years, and I haven’t clue of wheel shaft sizes or rudder and trim tab sizes or quantity..my only option is to use a diver, and he insists on owner procurement of said Zincs beforehand or pay for a double dive and appt. ..available items are available 3-6 hrs and 100+mi round trip to nearest stock..dry haul is not a feasible option…yet. Thanks to any and all help ..and no, previous owner kept no such records??!