</font><font color="blue" class="small">( Would these manuals be very expensive? )</font>
Not very expensive. Your purchase isn't complete without operation and parts manuals.
</font><font color="blue" class="small">( and is there any way of finding out what age my YM 1700 2WD would be? )</font>
First series was pale green with external headlights on the side of the hood. Early 1970's.
Second series was red with headlights in the front of the grille. About 1976 - 79.
Both series are indestructible classics. I hope the seller didn't tell you it was a 'new, reconditioned' later model!
Yanmar never distinguished model year, just 'revision level' for ordering parts. Your parts manual will have more detailed information.
The US versions of YM1700/YM2000 were YM195/YM240.
US differences were minor, notably an over-run clutch inside the PTO. (also the pale green was continued into US second-series).
You might like to look at the YM240 sales brochure in my sig photos. It lists detailed specifications.
Welcome aboard!