The rear brake plates are the original magnesium racing items.
The sprocket is a lightened item and will be left. The original finned drums disappeared when the bike was in bits ‘n’ pieces many years ago – it is suggested that someone who went to look at the project took them away with them as they were a desirable upgrade over standard road-going unfinned items. Drums fitted to the rear differ in that one is drilled to prevent water build-up. Shoes are good with plenty of material. No bearing seals were fitted but there was no grease contamination present.
Grey Flash 2751 
Humph, no bearing seals front or back .. we lightly oiled the bearings before a race meeting .. other wise too much friction
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Still as you last raced it then!
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