Andrew,
I am pretty sure that the LDMCC's '1920s on' are the ones which will fit the later 2-3/4hp and EW. They must be made to fit either application, as the original factory part numbers are not the same.
Douglas used part number 1581 for the late 2-3/4hp (1920 on) like the TS and CW.
The EW uses part number 2016. This race also is used on the A31 and DT models. The same part number continued to be used for the top headstock bearing on the large side valve Aero models up to 1938.
-Doug