I think these should fit either a S.B., a Boxford, or maybe an Atlas! The Hand Rest is an Unused genuine Myford (part number: 73/1956), Price: £25 ; The 'Steady' (labelled ASTER 8/120)is the type that has an under-clamp piece which fits below the bed. The bed gap being 2" between ways. Maximum diameter for workholding is 2-3/4", and the 'V' is 1/2" wide. Price: £45
Also for sale is a substantial Fully Swivelling Milling Slide in excellent condition - Bed size =160mm by 88mm.(so larger overall than the usual Myford size) Price: £90 (ovno)
Close -up photos on request if you send me your email.
Richard: 01366-728030 (West Norfolk)