Aaand let the over thinking begin
10mm Allen key gets that Uniglide cassette and freehub off, once you have removed the perfectly boring standard axle
Don’t throw anything away
Yet
What do you want from the wheels?
If you want to stay with 6 or 7 speed, lob a 7spd freehub body on it, rebuild the axle, 7spd cassette and off you go
But wait! Vintage looks but with more speeds! With the uniglide freehub body sat on the side worrying about its future, you can now fit an 8/9/10spd freehub body which would then give you 8/9/10spd shifting options
Yes, you will have to redish the wheel to recentre it and yes you will have to play around with the axle and spacers to suit the frame fitting but, hey, who cares, you got more gearz innit!