High Nick. The most useful type is the Dickson "quite-set" where cutting tools are kept permanently in place in drop-in, height-adjustable holders. Once you've used one of these, you won't want to go back to packing up tools with lengths of broken-off hacksaw blade.
The original UK-made units are very expensive but there are many copies now available - though the tool holders are rarely interchangeable between them. As your lathe has a 4-inch centre height, one for a Myford might suit, but it could need a raiser plate beneath the central block to be effective.
RGD tools sell them (though their choice is rather limited at the moment) as do
Chronos who have a far better selection - and also
have an offer at the moment for sets of extra holders. You'll need a set with a minimum of four holders; if fewer, it negates the whole point of them which is to set the tool height correctly and keep it in place, just dropping it into position when needed. With four holders you'll have a parting tool, boring tool, knife tool, and a finishing tool all ready for immediate use. Prices range from around £70 to £130.
A good alternative is the Chinese-made "
piston" type in its smallest version. These have five holders as standard: boring, parting, knurling and round (though the last sometimes comes as a No.2 Morse taper). If you buy one of these, get a couple of extra standard holders at the same time. I've sold lots of these over the years in all three sizes and have been OK.
A much cheaper type is, of course, a 4-way toolpost,
like this and sized to suit the 4.5-inch centre-height Boxford. Don't worry about it being made in India, all the Chronos Soba stuff is made there as well - as are many of their other engineering bits and pieces.