Can't identify model or serial number of a used Yard Machine by MTD

I just purchased a used Yard Machine by MTD 7 speed shift on the go.
I can't seem to find the nice fancy MTD sticker that contains the serial and model numbers.
But, under the seat, I found a sticker with a bar code on it.
Under the bar code it reads: TRACTOR: 42SD 1750 Series 1STY

Earlier today, I call the MTD 800 number.
And although the person I spoke to was very nice, he said it couldn't find the above numbers in his "database".

I'm trying to find a user manual so that I might learn how this machine is SUPPOSED to operate.
And, I want to order a mulching kit for it.

Any ideas what I might to next ?

Thanks

If this looks like your machine then here you go.
http://www.mtdparts.com/equipment/mtdparts/yard-machines-riding-mower-13an772g729

It sure does !

I thank you.

Ray in Wisconsin

By the way I used "42SD 1750 Series 1STY" copied and pasted from your post for a google search and found it at the top of the list.