Grant - don't know if you made any decisions yet or if you're still looking. Wanted you to know, since your ad mentions "qa-36 or qa-42" for your 1250. Neither the QA-36 nor QA-42 will fit a 1250. You need either a QA-36A or a QA-42A. There has been some discussion that the letter A suffix indicates "adjustable" since it is made to fit (adjusts) to either a narrow or wide frame and your 1250 a wide frame. Also, you mentioned "blower" in the title of your ad. Both of these are single stage units (because they don't have the 2nd stage fan blower), but I can tell you from experience when they are in good shape they really do throw the snow and work especially well on a Hydro tractor like your 1250.
The thrower David Schwandt has is a QA-42A which is correct for your tractor. Looks to be in pretty nice shape too. I also see it's a 4-paddle auger version which does apparently work a little better than the earlier 2-paddle style.
I believe the thrower that Bill Trammell has is either an H-42 or H-48 later production thrower made by Haben for IH and CCC. I believe it was designed for the later spread frame tractors (82 series and later) and probably will fit your 1250, but I never had one of these and don't know how they operate. I will say it looks to be in pretty good shape and that sounds like a really good price but I just don't know what they really sell for in the mid-west.
Good luck with your hunt and let us know what you do by another posting to your ad here.