Certainly not a bad looking cub and the 1650 should do anything you need it too. I believe you can get a cat 0 3pt for it can be pricey or the sleeve type as you state it is a bit cheaper but both will work with the hydrolift already on the tractor if all the proper parts are used. I have a 1200 and it's starter is not noisy but what is he comparing it too? I'd make sure to have a look at the oil before and after running it. Of course no smoke would be preferred. Check under it for drips from the hydro rear not real big deal but would require some skills to repair. Make sure the while driving for that it maintains the speed well no matter of speed, if it accelerates unexpectedly it's fixable but price offering would certainly go down. Everything on these tractors are fixable but do drive up the costs if all he has done is make it look pretty but it needs alot of parts to make it reliable they add up quick. Some folks put automotive style coils on them and they don't last nearly as long as the kohler coils they will have something like for external resistor use only on the side of it. Last new one bought cost 50 bucks not a big deal but every little adds up if you have to do it. Look over the deck to see if he has ever greased it you can wiggle the blades up and down and tell if they are good at least the end ones are easy. Make sure the pto engages and the blades actually turn
once running verify hdro moves up and down freely. Ask if he's ever replaced the flex couplings on the drive shaft as if not they could be worn but may be good depending on the use.
As good as it looks i imagine it's in pretty good shape, but something my dad always told me and has been true for cars i've bought if it looks really nice sometimes its just shiny on the outside and trash where it counts.
I've bought 3 so far one 128 for 50 basically parts but runs, one 1200 that Duke and I both have
each other up for LOL It is a smooth mowing machine and a 149 and all i can say is they are all very capable tractors and whether you end up with that one or not the one you find you will enjoy! I personally love the hydro lift my 149 has so I'd say get the 1650!! These guys will tell if the price is right... my 149 was 275 with new ags and I adjusted a few things and its running over all i've prolly put a few more bucks into it adding all the parts and accessories getting it the way i want it. Plows and tills and pulls a box scrape with no problems. My neighbor with a compact JD says wow that thing is stout and tills nice!! LOL and yes i'm bored wanting to go play outside today...
oh and they actually were built with Steel!!!