To put it bluntly, this somewhat strange (and extremely rare) model was a bit of a failed experiment for Con-Cor. It all started when Charlie Vlk (a Con-Cor employee back in the day) purchased Victor Napolitano's remaining supply of Erie-Built shells (originally sold under Victor's "V-Line" brand). Some were painted for PRR, UP and NYC (paint by Dallas Mallerich of Loco-Motives), and the rest were undecorated.
Con-Cor did modify the shells slightly - window inserts and horns were added, and the forward step-ladders were removed (to provide the front truck more room to pivot). Said shells were then either mounted on a Con-Cor PA-1 "dummy" chassis, or a slightly modified PA-1 power chassis. The modifications to the powered mechanism were limited to (as near as I can tell) some grinding here and there to accommodate the Erie-Built shells. Additionally, a small piece of plastic was removed from the coupler pocket on the forward truck of the powered unit (to allow the coupler to fit through the hole in the shell). Both units (powered and dummy) have directional lighting.
These locomotives were released (most noteably) as part of a limited edition PRR passenger train set. The set included one powered locomotive, one dummy locomotive, and six passenger cars (Heavyweight Baggage, Coach, Dining, Observation, Pullman, and RPO). List price was $249.98. Locomotives (powered and dummy) were also sold "ala carte". And although I have no idea what the production run on these might have been, my guess is that it was extremely limited. In five years of monitoring eBay auctions, I've only encountered a handful of the PRR sets, and exactly zero of the ala-carte locomotives.
Rarity factor aside, these are pretty pathetic locomotives (which probably explains why Con-Cor dropped them so quickly). Yes, the PA-1 mechanism (originally created by Kato in the 1960s) is a reliable old warhorse. And with the shells removed, these models do perform adequately. IE, relatively smooth, relatively quiet (although a bit noisy by modern standards), able to pull a decent sized train, and a little high on the starting speed.
However, put the shells on and the trouble starts. The truck-mounted pilot coupler has virtually no room to pivot inside the pilot, resulting in all sorts of calamities. Plus, the missing plastic above said pilot coupler's pocket makes for a Rapido coupler that's ready to jump ship at a moment's notice.
I suppose all of these short-comings could be addressed by simply removing the truck-mounted pilot coupler in favor of a shell-mounted one (or none at all). But, as delivered they're pretty much useless. And anyway, there are other better Erie-Built options out there (IE, Life-Like). So, an interesting experiment from Con-Cor, but ultimately one that didn't quite work out.
(Thanks to Charlie Vlk for providing the above historical data)
The V-Line shell was reviewed in the 4/88 issue of Model Railroader: ("This body shell, representing Fairbanks Morse's 1945-1949 era, 2000-hp Erie-built passenger locomotive, is a welcome addition to the not-too-extensive line of N scale motive power. The manufacturer admits to taking a few small liberties with the proportions to adapt the shell to Con-Cor's fine-running PA model, but these slight adjustments have no unfavorable effect on the model's overall appearance. The plastic casting is clean, and the details are sharp. There was a little flash on our samples, and most of that was around the steps and easily removed with a sharp knife. There are slight raised parting lines on the nose at either side of the headlight... I noted the headlight is positioned a bit too low...$15")