I've just had a brief look too. Exellent stuff sir!!
Helmet identification is one of the toughest arts to master!!
Used to be terrible when everyone had a white band around the top third of their helmets to make room for a certain well known cigarette brands identification!
I remember once sitting next to my dad in a temporary grandstand at Redgate at Donington Park watching the F3000 cars come out of pit lane towards us. The guy next to me saw the two works Ralt Honda's in distance and he asked me to tell him who was who because he didn't know.
I said: 'I do'
He said: 'How, their miles away!'
I said: ' i can tell by their helmets. Moreno is in front of Gugelmin.'
When they arrived he looked at numbers and said
'Bloody hell, you're right!'
I was quite young and bit embarrassed about it!!