my wheeler ( has no mounts ,, yet I have seen wheeler 9's on C/l and they have motor's and in portable case's
fact the bulk of the wheeler 9's showing up are motorized and portable , some of these motor have a strap type mount with a hole on each side, I have seen one's where they have just screw the motor to the base ( wood) and simply ran a belt to the hand wheel...
remember in 1910, teh little ye ol sewing shop wasn't just a short drive away.. and ordering online took a bit more than overnight ..
I read that singer did copy wheeler's design for the first few yrs, then started doing mod's to that machine. I would think the first mod may have been a motor mount or maybe just screw hole in the body..
whites first motor mounts where just two screws on teh back of teh column , which would be a very easy thing to do on a w9 / 9w