Hi forcutty, not sure how your knees are but I have a 6 speed 13,15,16,17,18,19 cassette, fairly sure it's uniglide.
The top 5 sprockets are combined, then a spacer, then the last cog screws onto the external thread on the free hub.
It's been buried with its hub, FH-1050, 36 hole and the freehub feels ok.
No axle or bearings but the surfaces look ok and the cogs don't look worn at all.
£5 plus post, got a shock with 1st class recorded last time !
pm me your address if you want it sent.