The Ryan's case is 10k Gold Filled, mostly in yellow but also in white.. The sterling silver dial has solid 18K gold roman numerals and markers. The dial actually came in two options, a two-toned white butler dial or a black nickel finish dial.
That makes for an interesting watch in its own right... different colored cases and different colored dials. I always thought the Ryan came only with a 12/0 sized, 17 jewel 752 movement. However, I recently restored a Ryan-B for a friend in the UK with a different movement.
When Hamilton discontinued movements but continued the model, they added a "-B" to the model name. There are lots of -B models but they were not usually listed in the catalog though. I always thought there was just a Ryan but that is not the case.
The Ryan B has a 17 jewel 747 movement - which was produced before the 752 was introduced and also after the 752 was discontinued. So I would assume sometime in 1954 the Ryan-B was made.
As received, the watch I restored was in fairly good shape but the dial was faded and lost most of it's markings. It was missing the second hand and the hour hand was incorrect. It didn't run very well either. Other that that, it was great!
UPDATE - Jan 2, 2015 - I happened upon another Ryan-B, this time with the white gold filled case and an original black dial... very nice!