I think that we're talking at cross purposes here, the SPIN selection refers to the Mark 4 autopilot used on Lancasters which ran off an Arrow air compressor on number 2 engine at 45 p.s.i. The control cock was on the port cockpit wall and had selections of OUT and SPIN if I remember correctly. SPIN was checked before take off to ensure that the gyro was spun up and ready for use in flight. The same autopilot may have been fitted on early Hastings but I never saw one.
The Hastings used a Mark 8 autopilot, which was worked by electricity.
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By the way, has anybody ever seen an autopilot officially referred to as “George”?