The silk hankies are surprisingly quick to spin from the corner - I'm going to get Ken to video me doing that in the weekend, and I'll post it then. I have already been doing this with my spindles, but I'd never spun from hankies from the corner with my wheel before - I'd always started pulling them out from the centre and attenuated into roving. Spinning from the corner is so much easier and goes so quickly.
So: Z-spun core of merino/silk (so old I haven't any idea what the proportions were) with lots of twist, mohair singles spun from my own batts, also high twist, plied S with medium twist; binding thread of fine silk, medium S-twist, to be plied Z with the 2-ply. We shall see!