Like information on a Darracq Boss and another

[Parsons]

Hi,
I wonder if anyone could help me identify two early propeller bosses my father had.
One says Darracq Motor com and other has a lot of letters and numbers but I do not know what they mean.
He needs to sell them and would like to know what they are from and if they have any value as they have been made into a clock and a barometer!
Any help would be gratefully received.
Photos attached. I have included the small boxes on one of them.
One says ‘ DARRACQ MOTOR ENG CO LONDON,2021, RAF 4A
The other’ FE2B 120 A to Dlr, G98N30, T5638,PTB 5.35, G98 N30

[Dbahnson]

The first one specifies the engine, a RAF 4a, which was used on a number of different aircraft, and there is no way of knowing which make and model it was designed for based on the stamped information.

The second one is clearly stamped for the Fe2b . The "T5638" is the drawing (blueprint) number, and the "G" and "N" numbers are production numbers.