Thank you, Jack
I have found that the fan housing/rug noggle, or base, on the 150's can vary in color very slightly depending on the year that they were produced. The original color on mine is sort of a lilac grey.
As to 150 bags: The proper 150 bags on the US models, all appear to be underlined in a standard blue.
My bag is actually off of a very late 1938 model 300 that was purchased from the original owner. The 300 was sort of the junior machine to the 150. Much the same as the 450 being the junior machine to the 800.
Long story short, everyone at the VCCC convention, five years ago in Milwaukee, swore that I had mistakenly hung a 150 bag on my 300. So the story goes.... I replaced the bojack bag on my 150 with the 300 bag, and that's why you see the unusual 300 green underlining rather than the proper blue. Otherwise, but not totally, the bags are very similar and close enough to the ordinary eye. As is often jokingly said here in the states "it's close enough for government work."
--Bernie