One of only a small number of dedicated, miniature surface grinders have been made world-wide - the others encountered so far being the American Sanford, made in New Jersey; the pre-WW2 Herbert "Ball-bearing Bench Surface & Die Grinder"; the French Lipmec LIP 515 and the Grenby by an American company (better known for their cylindrical grinders), whose slightly larger table-top unit appears to have been adapted for the Australian Macson and, in recent years, also produced in China and sold under various brand names including Harbor Freight and Tormach.  The Tormach, produced to a higher level of accuracy and finish, is available with automatic feeds and has travels of 6 by 12 inches - travels for the hand-feed Grenby are not known.
If you have a Macson or Grenby surface grinder, or any literature concerning them, the writer would be interested to hear from you