I put a deposit down for the 127.
The seller of the 1650 never replied. But I did go test drive a 1250 to see a Wide frame made in the same period. There were some issues I noticed with the 1250 that the 127 didn't have (ex: I didn't have to press the clutch/brake to drive forward/reverse, there was a leak under the rear gearbox / hydro, ... but she did look great!)
The 127 just "felt" right. The seller was the original owner's daughter & son-in-law who got it after he passed, it was used on his farm, and they still had parts that their dad had used: snowblower, plow, sleeve hitch (with DIY hand lift), chains, Cub Cadet spare blades, and manual. Everything is rusty and worn but it all works and that's what I kinda wanted.
What initial maintenance should I do? I should probably post a new thread on that.
You shouldn't have to press the brake pedal (there's no clutch on a hydro cub) to do anything but start the machine.
127s are great machines. I've got one somewhere. I've got pictures of it at least!
Sounds like you got a pretty complete machine and that's not an awful price for everything you got. The accessories are a bigger deal than the tractor in a lot of ways. Tractors are kinda a dime a dozen, especially in the 1x4/5 and 1x6/7 line.
There really aren't too many things to do on these machines. Basically change the fluids. The rear end takes Hy-Tran or MasterTran (from Case/New Holland...not the cheap crap from the farm store). You should change the filter with an OEM one as well. You can still get those from the CNH dealer. I've also had good success with Wix 51410 filters as well. Change the oil. The book says straight 30 weight in the summer and 10w-30 if you're going to run it in the winter. I use Case Low Ash SAE30, but any good quality one is probably fine. I don't run my K series engines much in the winter, but really any decent 10w-30 should be fine. Those things were designed when oil was pretty crappy, so even the cheap modern stuff is way better than what they would have run new. There are a handful of things to grease on it, and you should do that too.
You could give it a tuneup too, depending on how handy you are. Change the air filter. Check the carb bowl and possibly rebuild it, inspect the points and set the timing, new plug and maybe wire, depending on how crusty it is.
Then give it a good bath/cleaning, especially under the seat pan if you can. Grass and crap tends to accumulate on top of the rear end and keeps it from cooling properly. The rear ends are pretty indestructible in pretty much every cub cadet at least through the late 90s, so no major maintenance there, but they should be kept clean.
The common things that wear on those older machines are the steering box and linkages, wiring harness (something about the 1x6/7 machines in particular for some reason), and possibly the trunion (which is a massive PITA on narrow frames compared to wide frames) if it won't hold a set speed or is jerky in forward or reverse. The cork gasket that goes between the hydro unit and the final drive can leak too. If yours isn't leaking you're probably fine.
Other than that it's the standard stuff. Bearings that wear out, linkages that are sloppy, driveshaft through-holes that get wallowed out etc. It's a 50 year old machine. Stuff is gonna wear out.
On the blower, make sure that the auger spins freely and that the driveshaft is alright. The gearbox and sprocket are usually the things that go TU on those.
That's the list off the top of my head. I'm sure other folks will chime in as well.
Welcome to cub cadet ownership!