I bought some Sintered Bronze Bars awhile back with intentions of making Gibbs for my Lathe but havent really needed to. Maybe you could use some on your Mill...It is Oil Impregnated Bronze and Things would stay Oily and the wear factor would be on the Bronze side and not the Cast ways.. 01 will chew cast iron up in a short while...I think The Bronze would be the deal...
Here Is a Link to the Bars..
https://sdp-si.com/eStore/
Bob