I've bought some of the parts from the first seller,several times, from Malaysia, and all seemed to be NOS original. The second seller says in description " all parts reproduction unless otherwise stated"
Yes, this chap is honest, prices are fair and the parts arrive very well-packaged in about a week or so. Descriptions can be vague and you must be able to recognize what you are after. He has a huge trove of BSA military and police parts, including B31 and A50. Used parts are clearly marked as such. I've bought dozens of parts from him.
It appears that some NOS bits like gears have had surface rust that he cleans by bead blasting. The B31 cylinder studs come as bare metal, for example.
Yes I've bought a few parts from him and received one of his NOS clutch centres a week or two ago, I was just curious when I noticed the chamfer was different in my part list and different to the other one on ebay.
He is on my daily watch list.
I'm actually quiet surprised how many NOS parts I've managed to source in the last month since I started looking.