Lads; the MK 1 referred to in Posts 1 and 2 seems to be XA908. The other loss was a MK 2, XL390 and referred to at Post 4 and, I believe, 3. I'm not intimate with N American geography but I'm sure Detroit and Chicago are quite far apart.
If you follow the link in Post 4, you will probably find all the Vulcan information you could want.