1952 series 62 Brake Master cyl cap

[Technician!]

Is the filler cap on this under floor master cylinder a unique size to our vehicles, or will any cap and seal for this era car fit?

[fishnjim]

See below.

I think last time I had to obtain a MC cap, I found a new one from another brand parts vendor(Merc?).   I think they're mostly Wagner's but not sure what the wagner P/N might be or if in repro but they're the same for a few years per parts list.
You can also call one of the rebuilders, like Whitepost, etc and see if they have.   

[Technician!]

Thank you for the links.  I want to get another cap to modify to install a remote filler for reservoir.

[Jay Friedman]

Thank you for the links.  I want to get another cap to modify to install a remote filler for reservoir.

To install a remote filler, you must obtain a '54 or possibly a '55 cap.  Caps of those years have a pre-drilled and tapped female compression fitting for a tube running from a remote reservoir.  Such a cap will screw right into your '52 master cylinder.  At the same time you must get a'54 or '55 remote reservoir, which you mount on the driver's side inner fender or the firewall, as well as the steel line between the M/C and the reservoir.

I did all this on my '49. 

[Technician!]

Thank you.  However, originality is not necessarily as important to me as function is.  I thought I was smart and found a 54 cap for sale, but alas...it was half the price of a reconditioned master cylinder, so I passed.  I will just modify one that fits (hence the original question), and fabricate my own configuration.