I just received 3 team "real photo" postcards from 1951; Benotto, Bottecchia,and Legnano. There are some interesting details in these shots:
All 3 teams were using Campagnolo Paris-Roubaix rear mech that season.
Looks like Universal "Extra" calipers and Mod.50 levers on each bike, but the Benotto of Antonio Bevilacqua seems to have a much larger adjusting barrel added to the brake caliper - looks like a barrel from a lever attached somehow to the caliper barrel (for easier adjustment while riding?).
Nice clear picture of the Universal Mod.50 levers with half-hoods in the Benotto picture.
Bevilacqua's Benotto has an Ambrosio "Champion" aluminum stem with vertical clamp bolt, not horizontal like later Champion stems.
Bevilacqua's legs appear to be hairy.
The Benotto and Bottecchia bikes have Huret front mechs.
Short front fender on the Bevilacqua's Benotto and Bobet's Bottecchia bikes, but none on Soldani's Legnano.
A young Giovanni PINARELLO is pictured with the Bottecchia team.