JD 170

Hello

I've just acquired a JD 170 riding mower. Despite its age, it looks in very good condition apart from a couple of tears in the seat.

I'd like to get a manual for it but there is no sign of the S/N anywhere on the mower. I have looked all over the chassis, under the seat, you name it!!!
The Deere Bookstore lists 2 manuals depending on the S/N, so my question is:

Is there a huge difference between the JD 170s? I really just want a basic user's manual - what each switch does etc. so could I just get either of the 2 manuals?

Manuals:

OMM 78999 for S/Ns 595001-750000, 595001-

OR

OMM 95262 for S/Ns 010001-100000, 010001-420000

Any advice would be greatly appreciated, but please be gentle as I'm not technically au fait with garden machinery!!

Thanks