Update : the gearbox is in!
The chassis mount was within 1mm, and the aw11 shift cables mated perfectly. All 6 gears and reverse can be selected with no problems.
The c160/blactop combination has an alloy stiffener that joins the lower block to the gearbox. This needs to be ground away to clear the aw11 rhs drive shaft - I removed approx 8 mm of metal, but managed to do so without any issues.
A successful conclusion.
Thanks to Aaron Willis for help with part selection for the gearbox, and John Ellis for fabrication of mounts & brackets.
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