Hi,
Any luck, you never replied!
Just an update, there's a discussion on the NOC websire re-Domiracers of the 1960s also even though I poo-pooed them as possible race bikes in the early 1950s, the 29bhp @6,200rpm I quoted, was for a UK plunger- equipped suspension, Model 7 Dominator of 1951 a civilian mount.
You may have better luck contacting someone from, or that was employed by the Berliner Corporation @ that time, in the early to mid 1950s, they were the main Distributors in the USA for Norton products up to the industries collapse, some say, suicide!
Just as an example of what they would have been up against:
350cc Gold Star
1949 25 bhp @6,000 rpm;
1953 27 bhp @ 7,000 rpm;
1956 32.5 bhp @7,500 rpm;
500cc Gold Star:
1953 34.5 bhp @ 6,400 rpm;
1954 38.2 bhp @ 6,500 rpm;
1956 40.4 @7,000; boosted to a possible 42/43 bhp with megaphone & a few mods;
Best Race Shop special:
350cc 37.5 bhp @8,000 rpm;
500cc 48 bhp @ 7,500 rpm both measured on a hydraulic Froude Dynamometer Type DPX, by Froude Engineering used to test all Gold Star engines from 5,000 rpm upwards @ BSA's premisis.
Cheers
John