Yet another Portass from the late 1930 to late 1940s without a model designation - and of a type that must have been produced in very limited numbers. In addition to incorporating easily-recognised elements of the Model S (including a complete lack of guards over changewheels and backgear) it has a variety of features quite at variance with normal Portass practise: the centre height is four inches (unusually generous for the maker) with sixteen inches between centres; bed and headstock are cast as one - though this is in line with the maker's early miniature lathes, the first Model S and the Type V - and fitted with a tumble-reverse drive to the leadscrew. The headstock pulley is obviously intended for a Z-section 10 mm belt (and not a round rope drive) and the spindle nose, with a 1.125" 12 t.p.i. nose is either a modification by a previous owner or a quite-out-of-character move by Mr. Portass. The bronze leadscrew nut is full, and obviously of the maker's type, through the handle on the dog-clutch is not theirs. Oddest of all, though quite possibly a modification, is the well stepped-out cross-slide screw support bracket, the micrometer dials and (for a Portass) the unusually delicate T-slotted cross slide. With the extra rearwards slide travel obtained by the screw bracket, all these fittings combine to equip the lathe perfectly for the mounting of a vertical milling slide, However, even if these items were replaced with ones from an ordinary Portass, the lathe would still appear sufficiently novel  to stand out. Just possibly, it might have been built for the then famous tool and machine-tool distributors Buck and Ryan; their badge is attached to the lathe and they would have had the buying power to purchase a batch of machines made to their exact specification. However, having decided upon tumble reverse, one wonders why they did not specify a proper apron with clasp nuts for the leadscrew and a rack-and-pinion hand drive for the carriage ? And could they have neglected to specify at least backgear guards when all other small lathes were decently covered up?
In many ways this models answers most of the usual and annoying shortcomings of the smaller backgeared and screwcutting lathes from Portass - with a few simple additions it would have made a tough competitor for the Myford ML10 - if not the ML7.
Another unknown model type is shown here
If you have a similar machine, please do make contact.