Nice review and information. I'll add what I have found.
I bought a 1377C out of renewed interest and nostalgia, from using my dad's Crosman wood handled 130, which still works, though, sounds like it needs lubed, because of how little air moves from 10 pumps.
Anyhow, I just received today, the Shoulder stock (part number: 1399, through the Accessories section of their website)
Yesterday, I received a replacement Pump Handle, in black (part number: 1389-010), 2 Set Pins for said Pump Handle (part number: 1300-009 [1 each]), a Right Hand Pistol Grip, in black (part number: 151-019), Left Hand Pistol Grip (part number: 151-020) and two Pistol Grip Screws (part number: 105-054 [1 each]).
The Pump Handle is thicker, contoured and black, originally being mounted on the Crosman 2289. If you do a search, you can see pictures of it.
I bought two sets of everything, since a friend bought a 1377C as well, the same day. He had at one time, at Crosman 1322 Pump Pistol, so his was also a nostalgia type purchase, plus to have something to shoot with the rest of us, that was inexpensive. The two shoulder stocks were about $54 after tax and shipping. The two sets of pump handles, right and left pistol grips, screws and set pins were about $33 after tax and shipping. Both took one week to arrive from the time I submitted the order via the website for the stocks and via phone, for the "Replacement Parts" order.
I’ve also painted the front sight, the part facing the rear sight, a fluorescent yellow, with a couple layers of Glo-It Luminescent Paint, with a couple clear coats on top of that, which really helps with eye relief on the front sight. I would like to get a real Truglo sight for it, if I can find, fit, craft something to work. For now, all is good. I am able to hit spinners at 100 feet that are less then 1†in diameter, repeatedly, sometimes 3 or 4 out of 5 shots, while using bench to rest my trigger hand, and my offhand holding under original pump handle.
With the shoulder stock, it seems rock stable, even more so then bench resting and supporting the front under the pump handle, so we’ll see how it does this weekend.
The new pump handle is larger and helps prevent my pump hand from getting caught between the handle and the trigger guard. All the parts look nice, too. I may order the steel breech kit next, but, I have already spend almost as much on parts, as the air gun itself, so I held back for now. I don't intend to Scope at the moment, so all is good.
I have noticed velocities of around 550 FPS at 1000 feet above sea level, with Crosman Premier Lights, 7.9 gr, at ten pumps. I was able to get 200 FPS at one pump and lob pellets down range, 100 feet, to bounce off the backstop or shake, maybe knock over, some pop cans setup on the back stop, which causes me to laugh each time. You have to aim high, but, that's half the fun, actually hitting something with so little power. Three pumps, the recommended minimum, gets, from what I recall, around 325 to 350 FPS.
FYI. Contact with Crosman is best done by phone. I have yet to receive any reply to e-mail requests, either directly or through their online submission page, that were sent over two weeks ago with questions on how to order replacement parts. Contact via phone was a good experience, though. I used my cell phone, so, it basically cost me only time that I would normally be at work. It was quick; the Crosman representative was courteous and very helpful.
I've also had a lot of fun with my 1377C as well, sometimes shooting it more often, through a day of shooting, then my Gamo Viper. My poor Shadow has been barely used and sits black in envy in it's hard case.
Laters,
Tim