Hi Drew,
The Model 17 was basically a commercial grade machine and not designed for domestic use, thus why so many different variants were made for so many different applications.
Both my two machines are both powered by the exact same engine as yours is but without the reduction drive attached thus I have a standard clockwise engine output opposed to your anti-clockwise. Also my 412 Villiers are mounted the opposite way to yours.
The second machine has a great reel in it but it is an 18 inch machine, thus it's no good to you.
Depending on how much needs to be machined off your reel you might be lucky enough for just a light lick that needs to be machined so as to salvage the reel for another round so to speak. Honestly there will be quite a few more Supercuts that will surface for sale in the next 12 months and you won't have to pay any obscene amount of money to secure one, thus this will give you far more options in your rebuild.
Cheers,
BB.
PS. BTW where did the RG parts guide come from ? Grant ?