What he doesn't know isn't worth knowing. He gave me the grand tour and the chance to view his vast piles of spares, many, many diesel cylinder heads - he even demonstrated a test rig which is basically a bench to plonk an engine on, test & re-test. The thoroughness of his testing is reflected in his mantra of once it's sold he never wants it back!
Anyone wanting bits - don't hesitate. I came back slightly more knowledgeable and slightly skinter

One minor claim to fame - I told him something he didn't know about centre consuls (I said I wouldn't boast - but his staff insisted that I do!)
Cheers
Roy