Technical 1954 Buick question

I have a couple questions about My new 1954 Buick Century project. I want to check the master cylinder, Is it under the floorboard somewhere? It's not on the firewall.

The hub on the water pump is wobbling a little maybe due to a worn bearing. Is this bearing replaceable, wanting to find a way to fix it Myself as a replacement pump is hard to locate. I have the 322 Nailhead

 

I am assuming the the master cylinder will be in the same spot as my 55 special. There is an access hole on the drivers side front floor that you can get to.

 

Ok thanks, will look there

 

Yep, there's an oval access panel that pops off.

 

I have a 1954 322 Nailhead in my avatar, lots of parts available, got my water pump from Russ Martin: http://nailheadbuick.com/ he rebuilds old pumps perfectly, they're not from China