I've been thinking of drawing the M-107 for the train sim and thought I might be able to find a decent set of drawings on the internet for the MacLaughlin Buick to at least get the basic carbody proportioned correctly. I Googled 1938 MacLaughlin Buick and as it turns out, the M-107 is actually a 1936 MacLaughlin Buick and not a 1938 model.
Note the top of the radiator that was used on the 1937 and later models compared the the rad on the M-107:
The 1936 Roadmaster appears to be the same as the Cadillac, just without the spare tire covers. It also has the same trim along the hood as the M-107. I did find drawings but they are on a Russian site that coughs up a warning from Microsoft if you try to view the files. Too bad, they should have been just what I was looking for, three elevations and an overhead view.
I wonder if M-107 is labeled 1938 because that's the year it was converted to a high rail car.
This link does a good job of mentioning the 4 model levels with the top being the "Limited", which if it was properly reported as a limousine, M107 would have been a "Limited". https://en.wikipedia.org/wiki/Buick_Limited
Maybe there's a way to spot relatively what model the M107 was based on the quite difference wheelbases if we could figure out where in the bodylines they added the length. I have attached a chart of the 4 model lines with their wheelbases to start with.
I think it's a 1936 Roadmaster 81 (six passenger version at 132 inch wheelbase), just without the spare tire covers. Cadillac sold these as a "Continental Kit" in later years as an option, only a single cover on the rear bumper, maybe it was an option back then as well.
It appears the difference between the 80 series Roadmaster and the 90 series Limo was a rolldown window partition between the front seats and the rear seats. Don't think that would account for 7 inches but after looking at several picture of both models the carbodies look identical... guess I need to look some more to figure this out!
Like I said earlier, trying to figure out where the extra wheelbase inches show up should be interesting.
I think I see it in the rear doors. Maybe not all of it but definitely some of it.
By the look of the photo on the ash pit and the year (1947) it makes me think that the Buick was a few years old before they made it into an inspection car, so it well could have served it's purpose as the President's limo then been re-purposed.
I think there was some minor difference between the 80s and 81s along with four or five inches in the wheelbase, that made me think it was an 81. I'll have to do another search and find out why. I think it was suggested at the time it may be a 38 but there were some design changed that eliminated any 1938 model.
I still would like to draw one of these for something to run around the DAR route in, the website about has some nice interior shots that would help with the cabview.