Thank you Larry and Ian for your input.
I have recently been buying a few of G.S. Davisons books and have looked at the Continental Circus for relevant info, unfortunately I think from recollection Ted Mellors left New Imperial or his story with New Imperial ends just short of the 1933 Manx - a race that I am particularly interested in.

The reason I was concentrating on the 1933 IOMTT was to try and nail down just which bike was actually ridden by Cec Weatherby. It seems confirmed that he was riding a "works' New Imp.

Given that the 'works' bikes rarely escaped I doubt that Cec was riding a works bike here(Australia) in January 1934.

Both Jimmy Pringle and Cec Weatherby were selected by the Auto Cycle Council of Australia (ACCA) to be Australia's representatives at the 1933 IOMTT. Jimmy Pringle was actually slated down to ride for New Imperial in the Lightweight TT but for some reason it was Cec Weatherby who actually rode the New Imp in the race. It was acknowledged in the Australian motorcycle press at the time that Jimmy Pringle would no doubt bring some racing machinery back with him when he returned to Australia.
Both Cec and Jimmy were injured at the IOM and both were hospitalised. Jimmy returned to Australia before Cec. Cec returned to Australia by boat on 8 September 1933 just about a week and a half after my fathers New Imp was built and 3 days after the 1933 Junior/Lightweight Manx.
Cec at the time was involved in the sales of motorcycles presumably from a shop at Ashfield NSW.
Given the fact that Cec did not race a New Imp in Australia till late January 1934 it is a possibility for Cec's machine to have been used in the 1933 Manx and be shipped to Australia.

This scenario all hinges on whether I can come across some close photos of the New Imps used by Ron Harris and Bob Foster to see whether they were the two new GP Model 50's or were works bikes.

From the research I have done so far on Ron Harris, it appears he bought his own Norton to ride in the Senior Manx and he was in the business of selling racing motorcycles. It is also possible he bought his New Imp to go racing in the Lightweight and if this were the case he would be Model 50 Grand Prix mounted..
In later years he went on to run Lotus racing cars. It appears at the time of Ron's passing he had a 4 year old daughter, who just recently on another forum said that she had a lot of photos of Ron racing, so another avenue to chase up.

Perhaps someone on this forum might know if works bikes were allowed in the 1933 Manx.
I think I recall reading somewhere that until 1930 the Manx was known as the 'Amatuer' races, so would have the New Imperial factory have been allowed to enter Ron Harris and Bob Foster on 'Works' New Imperial's from the factory or would Ron and Bob have had to enter their own machines?? This might help narrow down whether they were on 'works' bikes or Model 50 GP bikes.

Again thanks for your help Larry and Ian.

I think I know who Ian is - a regular campaigner on his Model 50??

Also I have just received two photos from Chas Lipscombe here in Australia of a Model 50 being raced in most probably Australia that I will send to you Ian by private message.

All help appreciated.
Thanks.

Peter Shannon