I bought a used Rottweil 72 American Skeet in 2008. It came with 20, 28 and .410 tubes which have been identified as "original" Kolar tubes. I assume that these were part of the original sale.
It also came to me in a beat-up John Hall plastic case fitted for the gun and the tube set.
The price I paid was $1,400 and I considered a 'good' price. That is until a year and six months later the gun started failing to fire the bottom barrel (or, less frequently, the top barrel) much of the time. I spent about $240 on new firing pins, hammer springs and retractor springs (parts only, no labor). This seemed to fix the problem. For about two weeks! when the problem became worse than ever.
I finally sent it off to Laurence Pylinski in W. Virginia who told me that the gun was "off its face" (basically shot out) and needed a "..complete mechanical rebuild." $900 later (I know, I know, a complete ripoff but what'd ya gonna do?) I now have a seemingly perfect skeet gun with a tube set and a crappy case. Oh yeah, and the stock cracked around the time that it started mis-firing so I had a stock guy put a brass screw and some epoxy through the crack.
Anyway, these models were a quality guns when they were manufactured. They all have a dropout trigger assembly. Other than that they seem to be solid workhouses.
Buyer beware. These guns haven't been sold in the USA since about 1983. If it has a tube set you can bet it was purchased for competition which means that, unless it's been sitting in someone's gun cabinet for 15 years or so, it's probably seen a lot of rounds.