44 inch rear discharge mower on my 1985 craftsman 18 hp. would like more info on it

Good afternoon guys. when i bought my craftsman it came with a 44 inch mower with 2 set of swivel blades like a brush mower. i am just wondering if anyone has a part number for new blades and spindle. they cut great right now but the blades would need to be changed.

the model number that i have on the mower is c-61444.
here is a picture of the blade. thanks