The blurb Taylor-Hobson supplied with their larger machines (such as one I used at work years ago) suggested using them as copy-millers and even lightweight vertical mills for fine work. The latter entailed mounting a steady-bar between cutter-head and machine frame. Indeed we did use ours for engraving out the D-connector holes as well as labelling the aluminium panels for the electronic equipment the company made.
Nevertheless converting one to a vertical mill seems a bit chancy, but it should be OK used within its structural limits and without the pantograph, such as for clock-making.
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I have what I think is the same model, awaiting a bit of work, principally finding / making a cutter collet and obtaining suitable belt; but I bought it purely for engraving. A proper set of copy would be handy but I do have a rotary copy-wheel so all is not lost – just one character at a time and due care for proportional spacing..
I recall one particularly unusual task at work though. We had to make a stylus for a special plotter, and the body of it was two pieces of bronze shim folder and joined by slits and tags. The big problem was making the slits, maybe only about 0.3mm wide X perhaps 10mm long. I ground a cutter to a very fine tip, and used that with a large reduction on the pantograph. It took a few attempts as the cutter tip was so thin it broke easily, but eventually I succeeded, testing the slits with an off-cut of the shim.