[CWMV]

Indeed.
My only problem with the french numbers is that they had to run the low altitude tests with rads open due to cooling issues from not using the correct fluids. Especially when you look at the 5000M+ (Where the rads were closed) numbers that are well within 5% of the German numbers I posted.
Do I think that the rads being full open could take 40kph off the top end-you bet!

British tests with the same aircraft mirror those of the French, off the top of my head 16000ft was 355mph=571kph.

So weve got an aircraft that performs the same as German tests when you close the rads, and then is slower when you open them..seems logical to me lol.

And the Swiss tests were of an aircraft that had already gone through a third of its operational lifespan (if I recall 111 hours at test, retired at 350ish). In addition to this Kurfurst has summed up my thoughts on J-347 fairly well:

"Comparison of the speed results with Bf 109E prototype V15a's test report show remarkable similarity in the top speed achieved at altitude with the original VDM propeller of J-347 (572 vs. 564 km/h at rated altitude), especially when taking into account that J-347 already saw considerably use. However the low level speeds diverge greatly (498 vs 464 km/h at 0m altitude). However the low-level performance of V15a with the Höhenlader (high altitude supercharger speed, or 'F.S gear' in British terms) shows good agreement with J-347 at both high- and low altitudes.
This would suggest that J-347`s level speed results were achieved with the Höhenlader in operation, and the appropriate Bodenlader (low-altitude supercharger speeds, or 'M.S. gear' in British terms) was not used to record the results, therefore full performance of the aircraft was not reached below ca. 3500 meter altitude."

Regardless, the numbers call for a +/- 5%, so really Id be happy with anything from 470-500.
Ideally, to me anyway, 490 would be taken as a base, and a random power fluctuation within 5% would be applied to every 109, but I'm not sure the sim is there yet...

And yes, we all have our favored sources, but at least in this thread they were posted, and we can argue about the numbers rather than what we think the aircraft should do.

I suppose that's better...lol.