The second version of the Drummond flat bed illustrated below was considerably modified with new bed, headstock and tailstock castings and redesigned headstock bearings.  More details of these modifications and the machine's development can be found by following the hyperlinks above or looking here.
A warning to those who restore old machine tools - when it's time to remove the old paint, be wary about using paint stripper. Old-time manufacturers were not so concerned about the quality of the castings they used - and had no qualms about applying a filler composed of lamp black, fiddler's rosin and iron filings or "borings"  to cover up faults in the metal (an alternative was a mixture of sulphur, cast iron siftings and sal-ammoniac). The first mix, almost universally used, was known in the foundry trade as 'Beaumont's Egg' , possibly from a corruption of "beamontage", a filler used in the furniture trade. To hide minor faults in a casting Beaumont's Egg was run into blow holes and porous areas by melting it with a hot iron bar followed by rubbing down to make it almost undetectable. As an interesting aside the supplier of the cast-iron columns that collapsed in the Tay-bridge disaster used 'Beaumont's Egg' to cover his poor workmanship. Hence, the difference between a good foundry and a poor might have been the point at which a defect was accepted as being too large to fill, leading to a rejection of the casting. Unfortunately, early-filler soaks up paint stripper like a sponge - but then, being well absorbed into what are almost certainly porous castings, the  metal refuses to let go; the result is that paint will not stick and the filler has to be mechanically removed - another hazardous operation. Be wary of using a sanding disc or powered wire brush - even sound casting were often lead filled to smooth out the imperfections - and you don't really want clouds of that flying around the workshop, do you?