<sigh>
No 50 cal on the Spitfire VIII or the Seafires. The Spitfire LFXVIe that we have is the same as the Spitfire LFIXe. The E-Wing on late IXs, XVIs and XIVs was the wing with the 50 cal.
The Spitfire IX in game is a good balance to the XVIe as it really gives us two variants of the IX, a regular span C Wing version with the Merlin 61 and a clipped E Wing version with the Merlin 66.
I don't know that Pyro actually decided based on a few of us recommending using the XVI designation, but I will be forever sorry for it if he did, as it's been more trouble then it's worth.
It would have been much easier to have just called it the LFIXe and let folks skin XVIs on it, for those with a clue, as well as IXs.