It's supposed to be a 3208, but apparently it's actually an 1160 (or something like that). Ford called this engine a V200, and they were painted Ford Blue. If I remember correctly, this engine was a joint Ford/Caterpiller venture.
Nice progress on the engine. This might help with wiring it: http://public.fotki.com/modeltrucks25thscale/model_magazine_articles/car_modeller/cm08_july_1991_cate/ , but it looks like you've done a good job without it.
The black & white definately looks the periot (early 20th Century). To me, the sepia photo reminds me of The Old West or the Civil War. A little to early for cars.
Sweet looking combination. If you decide that you need a "change of pace" on the shelves, you could always put a water tank trailer behind it. Hey, after you build the pool, you need to fill it up, right?
Do you mean the Revell of Germany Kenworth W900 or the Revell USA Snap Kenworth W900? Either way, the AMT trailers fit these kits. On the Revell USA kit, you just need to make the hole in the fifth wheel a tad larger. Here's a pic of my Revell USA Snap Kenworth W900 with the AMT Fruehauf tank trailer:
Gary Wallace from GW Trucks offers a W900S, a W900B, and (2) different T800 cabs. You can send him an email at gwtrucks@yahoo.com. His W900 cabs are about mid-1990s. There are currently no cabs offered (that I know of) for the other T-Series trucks.