It will be difficult to identify an exact model. Balding Engineering, the makers, were not very particular with naming them. You could call it a VBRP Mark 2 with varispeed head.
It is a later model of their range: the Y-axis on the very early ones had a central 'hump'. The handwheels are the later, cheaper type. The feed gearbox is earlier than the one fitted to the PAL model. The worm to rotate (and knod) the head has a hexagon head - earlier ones were splined and needed a special spanner). The plaque on the front, which I think is a Queen's award for export or something similar, would help date it.
Right I acquired these what I believe are 40int collet holders a while ago on the off chance they would fit a future machine but this mill is 30int so they may as well go, I need to know exactly what they are for the advert if anyone can help?pics of the collets that fit in them if that helps
30 taper stuff is a little more difficult to find. Gloster Tooling have some. Maybe RDG Tools, maybe Chronos, maybe Rotagrip.
Learn all the various synonyms for 30 taper as it will help with your search: ISO 30, 30 iso, 30 taper, 30 int, SK30, BT 30, 30 international, NMTB 30, CAT30, QC30, DIN 2080 (include combinatons both with and without spaces).