Business car

I am thinking of building an O or G scale business car, probably starting
with a commercially available car, such as the 1:29 observation from
Aristo-Craft. Anyone have suggestions or sources re detail interior or
exterior parts? Or perhaps a better starting point?
Thanks,
Tom Spence
snipped-for-privacy@teleport.com

It's almost impossible to help an ambiguous request. Are you going to do O or G? What era are you talking about - wood cars, heavyweight steel, or lightweight? What's your favorite RR? What kind of prototype do you envision - car for president of a class 1, or just a division super, or for a shortline who's boss has an ego? Geezer

Sorry for the ambiguity. O or G depends on a reasonable starting point and available detail parts. A potential starting point is AristoCraft heavyweight observation No. 31400, a few of which appear on Ebay. The era is the thirties. The prototype I have in mind is PRR business car Chesapeake shown at pages 54 et seq of the 10/71 issue of Model Railroader.
Tom Spence snipped-for-privacy@teleport.com

If you opt for G gauge from Aristo-Craft, you might want to seek the Pullman car model as it has paired windows with intervening blank spaces much more like the window arrangement on the Pennsy Z74D business cars. The Aristo observation uses the same body at the coach, and the numerous single windows do not look like a business car. If you get the Pullman, you can the discard one vestibule and buy the awning and railing parts separately from Aristo. For detailing the interior, there is not much available in 1:29 interior detail parts. Your best bet might be to Google on "1:24 dollhouse furniture".
In 1:48 there are more options. The nicest model (short of brass) would be to look for a heavyweight observation form the old American Standard Car Co. They did 3 or 4 open rear platform observation cars, or better, did John Ringling's private car "Jomar" which has an interior arrangement very similar to the PRR Chesapeake. Interior kits were offered for each of these car kits. In other recent production, K-Line and Williams have done 3-rail O gauge observation cars, although many were shortened to 60' length. Going back to older 2-rail, the Walthers wood roof, stamped tin sides, and lead alloy end kits are very creditable models. They made several observation models, some of which still show up as unbuilt kits at train shows. Walthers also offered interiors, but these old interior kits were rather crude. Berkshire Valley and Keil Line offer interior parts or complete interior kits. Geezer