I have a bolens that was retrofitted with a pretty new 16hp vanguard v-twin that I really don't use. I haven't even started it in a couple years. Has a spin on remote filter and a steel shaft with a steel flex disc driving the hydro pump.
I think the battery is probably junk now. Needs a good throttle set up on it.
It has some newer ATV tires on it too. (Just never took it over any sweet jumps...
$400.00 very firm on the price - tractor is up in Luzerne (near Grayling)