I'm also starting back on my 1250 and there are no tags on the mower deck
I measured the overall width at 54 inches. Seems a little big but okay.
How do I determine if it's an a, b, c or ?? lol
I remember from last fall all three blades seemed equal in length.
The rear wheel brackets look like this model(not my deck).
http://ihccw.com/images/1002/IMG_5574_10.JPG