Ok, got the picture from Danny (see attached) and the casting date appears to be 194 (July 13th), but Danny, you need to check for the "assembly date" (located somewhere on the machined flange where the brake lines attach - see arrows). You may have to use some steel wool to clean it off enough to see as most of them have a VERY light stamp, if any at all. Note that July 13th, 1969 was a Sunday, so more than likely it's not a 1969 casting. July 13th, 1968 was a Friday, so it's "possible" it was cast in 1968, but unless you can find the assembly date showing the year, we'll never know.
Also note that since this cylinder has bleeders, it's a 1969 or later power drum brake master. I have no clue if this master cylinder was used on other models or other years, but if you can find the assembly stamp, it might narrow it down.
Ed
