Sorry for the late reply, guys. I was away for the Fourth of July weekend with very limited access to the Internet.
Thank you for the comments. It was a fun build, even if it was frustrating at times.
Jonah, the hoses in the hosebed are sewing elastic that have been darkened a little with Minwax Oak stain (at least I think it was Oak). The couplings are made from brass tubing cut to length with a tubing cutter. As it turned out, the tubing cutter scribed those lines on the coupler right where they are "joined". I have several articles from the old Scale Firehouse site that can help in detailing this kit. PM me know if you'd like copies. I don't think I have them electronically, so I'll have to mail you hardcopies.
Also of note, the vinyl tubing that AMT includes in the kit for the booster line is practically useless. No, it is useless! Replace that with some #18 electrical wire with red insulation. You'll also have to fab up some nozzles for the booster lines as the ones that AMT provides are actually 2-1/2" smoothbore nozzles. Way too big for the 1" booster line.