I found some new info DRG 5220 SC
GIPSY MAJOR 1C
and from my research GIPSY MAJOR was an engine used in the chipmunk Aircraft 1C denotes higer compression for racing engines
Referring to the list here: http://www.woodenpropeller.com/Britishprops.htm there are many listings for DH 5220 prop but I found none for the SC suffix. Perhaps someone else on this Forum will have an answer.
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