Nice looking Machine and $1400 (OBO) with the implements is an excellent buy IMO.
Small diesels that are well maintained, will go for decades. You very well could spend that much and plenty more on smaller, less durable lawn and garden tractors that are new(er) and gasoline powered. If the seller is close and willing to demonstrate the tractor, you might save money over the long haul. Consumables like oil and fuel filters are available. Hard parts like transmission gears, hydraulics and some electrical (starters etc.) are harder to come by.
There's a gent about a mile down the road from us who has a S373 that's split, with clutch, PP, and other componets laying on a trailer (with a for sale sign on it). I inquired about it last year....He said $2K NON NEGOTIABLE! The guy is nuts....and it's still for sale. Maybe he knows something that I don't know?
I have a Beaver. It's a great tractor. Unfortunately, Mitsubishi does not support parts in this country anymore. That said, you can still get them. You just have to send to Japan to do so. I used to live beside a dealer for these tractors. He's been retired for a few years but he's kept up with this line. When I need parts, I go to him. When we first got the tractor (dad bought it new) it split the pistons. We heard (after the fact) that this was a common problem on the earlier Beavers. After it was fixed, we haven't had a major problem with the tractor. Heck, we've hardely had a minor problem with it. I generally put it away for the winter because it's a hard starter in cold weather. That's NOT indicative of all Beavers, it's just that ours always has been, even when it was new. I can set you up with a couple of good guys that you can get parts from if you get this machine. I haven't looked at it yet but I would guess that $1400 is a pretty good deal on a great tractor. What's really cool about them is that, when you idle down real low, it's sounds like a two cylinder John Deere. Take a look on my picture site and you'll see my Beaver.
Keep this in mind, if you want to buy this for the purpose of putting a rear mower on it, they will only accept certain mowers. The PTO shaft is a small, fine splined shaft that turns counterclockwise. If this tractor has a reverser box on the PTO, that alone is almost worth the asking price.
No, I don't think that would bea wise idea. Besides, that's not the only thing to take into consideration. The size and spline of the PTO shaft will not work with standard equipment. He's right, that is a 2wd by the way. The Beaver has a three speed PTO. Here are the speeds with and without the reverser box.
1st: 517 RPM with engine at 2700 RPM
2nd: 762 RPM with engine at 2700 RPM
3rd: 1249 RPM with engine at 2700 RPM
1st: 537 RPM with engine at 2700 RPM
2nd: 791 RPM with engine at 2700 RPM
3rd: 1297 RPM with engine at 2700 RPM
Hope this helps. They make a great little mowing tractor if you can match them to the right mower. The only way you can use a standard rear mower is with the reverser box.