Here we go!
The VIA train, in 1981, made the following stops:
Havelock
Norwood (F)
Indian River (F)
Peterboro
Cavan (F)
Draneol (F)
Manvers (F)
Pontypool (F)
Burketon (F)
Myrtle (F)
Dagmar (F)
Claremont (F)
Locust Hill (F)
Agincourt
Leaside
Toronto (Union)
The Peterborough-Toronto trip was about 2 hours, the schedule set up for commuting.
Today, I would only have stops in Peterborough downtown, perhaps a park+ride in the west end, Pontypool, Myrtle, possibly Clairmont, Locust Hill for sure, Agincourt and maybe Leaside.
Other tidbits:
Toronto-Stratford enjoyed 5 round trips Monday-Saturday, 4 on Sunday. Toronto-Kitchener took 1 hour, 37 minutes. Toronto-London, 2 hours, 50 minutes. Times are somewhat longer now, but not by that much.
Toronto-Brantford-London had 8 weekday departures, travel time 2 hours, 5 minutes on the Tempo expresses (stopping only at Oakville or not at all), 2 hours 15 minutes on the locals. Travel times now are slightly faster, at 2 hours average, even making more stops, but only six trains a day.
Toronto-Kitchener and Toronto-Brantford-London are obvious as well for regional services in conjection with VIA.