There was some pics of the factory alignment tests for a l5a posted to .uk :. The manual you can download from the yahoo group (I think, Im not a member) will run through the rest of the controls but if you have any questions after ask away, I know the lathe fairly well, and adama I think it is has that exact model also amongst others. The headstock internal taper is some odd jarno variant, though in the end I just bought a used headstock bush from UK's ebay, as they are much more common on there.

You can lock the saddle to the bed with a bolt head that sits under the compound slide handle area, and there is a small allen bolt (think its 5/32ths from memory but I can check) to lock the cross slide also.

If you have a l00 nose, there are quite often jacobs rubberflex chucks and collets on ebay, sometimes at reasonable money. Im slowly collecting stuff to respindle to l00 this winter along with going back to a 3 phase motor with vfd and swap my 3 speed feed box to the norton one I have stashed in my cabinet ready. That model is a l5a, the norton gearbox and 11' motif put it as such, Also I believe I can see the l00 locking ring on the chuck, which should mean its l00 fitment chuck rather than the 2.25 nose although I don't know what other variants the usa variants had, although its not YOUR lathe just a stock photo so you can't rely on that yet as I bought a l5a and it arrived with a 2.25' screwed shank nose. Its a shame its been disassembled, the factory went to great lengths to shim the bed to the stand, which is a steel welded construction.

Harrison l5 lathe manuals