Okay - no more guesses received - so I'll tell you what I have found out.
Firstly, my old pal has confirmed that they are Staddens - and that they are a modular experiment which took place at Tradition of London - in that the heads, arms weapons etcetera were made to be interchangeable. This was discontinued later - and not transferred to any figures other than the knights. They could be older than 1960 - as they were in production this way, when my friend joined the Company in 1960 - so could date from the Fifties. They are therefore well over 50 years old.
From the left of my first pic. I think I have:
Harry Hotspur - wearing the cap of maintenance on top of his helm.
"A Norman Knight" - this figure is really the odd man out - as he has the typical long shield and is clad in chain mail with no plate armour. (see in background above).
Bertrand du Guesclin, Constable of France ( see above).
Thomas de Beauchamp, Earl of Warwick - in jousting helm with swan ornament.
William de Clinton - with head atop his helm. ( I think this is a good example of a modular figure - as the helm with head ornament is clearly a different colour metal to the rest of the figure - once the paint was removed. Again - see in background above.
King Henry V.
Delighted with them all - but especially the last figure - as I had been considering making a mounted version of Henry V - by conversion - for my "Agincourt" collection. I now have one - and he's a Stadden!!! Doesn't get much better than that.
Cheers all "likes" - glad you like 'em too. I'll be painting these up - rather carefully, in due course.
jb