From its design "The Sundale"  with its screw-on Selig Sonnenthal badge - would appear to have been made in the period 1880 to 1900. Some significant features, common on small to medium sized lathes of that time, included an outboard-mounted thrust bearing for the spindle; a narrow bed with an especially deep, detachable bridge section; crank handwheels on the carriage, cross slide and top-slide feeds (and a lack of micrometer dials); inverted V-ways on the cross slide; a bed-mounted rack of very coarse pitch, bolt-on hangers for each end of the leadscrew and a tailstock with the barrel section having fresh air beneath it. However, this particular example, with a double flywheel, full-length foot treadle with chain connectors (instead of flat-bar drive cranks) and machine-cut backgears, of better-than-average quality.
The use of the logo "The Sundale" in inverted commas was a common way of disguising - while at the same time admitting -  that this was a machine made not by the "Sundale Company, but by a manufacturer who wished to remain anonymous. With some resistance in the UK at the time to continental imports, there is a very good chance that the maker was German.