Its a different thing but seen the Aliminium Roland Vinyl cutter tool holders you can pick up on Ebay for a couple of quid used for some very fine drag engraving on wine glasses with a diamond tip might be worth a couple of quid to see if you can do anything with an aliminium tool holder very similar to this unit and a great place to start "rolling your own", it would be worth that to play and see may want to upgrade the spring and make a shank adapter. it would be light weight but that seems to be all you want
http://www.ebay.co.uk/itm/1Piece-Bla...4AAOSwHQ9WXBBJ