Ancient One
ArboristSite Operative
Since maximizing width of cut is a concern to you, here's something small, cheap and easy to get from lowes that might work. https://www.lowes.com/pd/Prime-Line-1-5-in-Steel-Sliding-Patio-Door-Roller-and-Axle-Kit/3083263
Looks like you can just get some longer bolts. These are only 1.5 inches, so only about 1/4 inch protrudes beyond the edge of your mill if you center the hole for the axle in the base of your mill. This would maximize your cutting width, BUT you may want larger because 1/4 inc can get swallowed in the bark. It certainly would with the pecan bark I'm cutting
Not sturdy enough for me. I will take a pic later today and post of the rollers I have.
I have a machine shop in the back yard, so fabricating a nice aluminum bracket to fit the power end of the mill to attach the rollers will be a piece of cake for me.