I can guarantee you that machine has an "aftermarket" motor. That machine is a fairly early 66-1 or 66-3 (The only difference is that the 66-1 was a treadle, the 66-3 was a handcrank). (You can tell by the tension and the stitch regulator) It wasn't uncommon to add a motor after electricity became more available...my DSIL, Peggy, (candela_59) has a beautiful Redeye in a beautiful parlor cabinet that was electrified and the treadle parts removed.
You already know to look for the needle to move up and down when you turn the wheel. There's been more than a few yards of material go across that bed, (decal wear, not necessarily a bad thing...depends on if you're looking for a "user" or a display piece) You're also going to need a spool pin...does it come with attachments? They can be pretty spendy for a back clamp.
I know it doesn't matter to some, but for me, the value of the machine would be less if it was drilled into to add the motor, and I'd be pulling that motor off anyway.
I would also pay less for a Redeye that's had the presser bar changed out to take side clamps. And keep the cabinet, you might run across a nice 201-2 that needs a "skirt"!
All just my opinion, for what it's worth! (not usually very much!!
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