I've used Lyford Classics for a variety of parts over the years without much trouble.
I had my motor rebuilt with many parts sourced from them including big/small ends, pistons, clutch parts, chain, gaskets. I've also had a saddle, cables, brake linings etc. etc.
The only problems I can recall were a dodgy taper on the clutch hub and an incorrect length cable. I've also had trouble with valve guides seizing but I think they were old stock original BSA parts and I'm not sure if Lyford supplied them.
Armour supplied new pipes and silencers which still look, and sound, superb after 5 years use but on receipt one of the down pipe engine bolt mounting brackets was miles out of alignment. They did replace it but not until after they'd queried my ability to judge as "we've never had problems before"