I have that one in my watch list as well Ben.
The #25 & 75 are exactly the same engine except the #25 has the belly heater & the #75 has holes in the firebox & of course a burner tray. I think the #25 pulls 3.5 amp & 400 or so watts ,yes, as Wayne said , a dimmer switch of the correct amperage will do nicely (I have 2 home made ones)