Sweet tiller Rescue! That is a 356 tiller, freaking heavy and IIRC it is 48" wide.
Here is what that tag should have on it.
DSC01719.jpg
Here is the one that came with my dads 982.
DSC01724.jpg DSC01727.jpg
They also made them for Snapper.
DSCN1376.jpg DSCN1382.jpg
They were also made for
Ariens TA-20A
Gilson
J. C. Penney
John Deere 35A -40 -300 -448
Massey Feguson 4850
Merry
Montgomery Ward
MTD
Roper
Sears
Simplicity 1600199
Sovema S-SE-ST
WheelHorse
Here is a company that makes the replacement tines. They should be part #R50C & L50C....I think.
http://cleancutter.com/cgi-bin/cctb_partno_search.asp
Another member, Dave1953 did a bunch of research on these also and I would check with him too.
Let me know if you need any more pics. I think I have a PDF of the manual if it is not on here if you need it.