OK, yeah I been reading.
You can spin off the Freewheel and spin on a track cog. Of course shorten chain, respace hub, redish wheel. Cost wise its about $30.
I've been to the shop. No, No! you need a Track HUB and re-lace the wheel (OK rebuild the wheel--OK replace it the spokes are crap anyway). Yeah its got to way safer but then it's closer to $75.
OH yeah chainline and might as well get a new chain.
The project is an old Lotus w/Shimano 600 gear including 170mm cranks on Steel Champion No5 lugged tubeset, 27" wheels with Weinmann sidepulls.