I need to replace a leaking master cylinder on a 66. If it is the original I would like to attempt to rebuild it. Can anybody help me in identifying it? About the only thing I can decipher is that it's a 1" bore. Assuming that's correct for a manual m/c?

Here is a pic of the numbers:

1st one in on the side. 2nd one is on the bottom.

Thanks!

Larry