The problem about using the original motor is, that its sitting in a bb-gun, and using it would require that it shoot pellets in order no to put too much strain on the gearbox, as the piston slams back and forth (the compression dampens the impact of the piston head on the cylinder backend). The gearboxes tend to crack when "dry-fired". So either I risk a gearbox, or I use a billion pellets stress testing the circuit for a few hours...
I see your point about the inductive load, though... Darn....
So maybe there's no way around field-testing?