So, I've got three and a half Dynasonics. Two complete Big R's and 2 that are partials. One of the two partials has a serial number of has the "Custom Built" badge with a serial of 45140
The others are as follows and are all Big R:
D751295
D758295
D604319 (The numbers are a bigger font than the previous two above)
Since I don't have the Rogers book, was wondering if anyone can pinpoint years and locations.
BBK