Clive, I just did a couple of lubricators with 1/4" bore roller clutches, using hardened silver steel shafts. they work fine, but if the gaps between the rollers fill up with heavy steam oil, seems to be about 3 months use, the rollers cannot move, and the clutch stops working, easy to spot, and a few squirts of WD40 or equivalent and oscillating the lever a few times clears the oil and away they go again. I had a friend who made one with an 1/8" bore clutch and he had the same issue, but more often, no doubt because they are smaller. You will need a pair though, one to move the shaft forward, and another on the opposite side to stop it rotating back. Alternatively you could use a ratchet to stop it turning back.
Chris Gunn