Didn't know I could find a 5 lug bubs
I wouldnt get all worked up over the 3 bolt hubs. I have a 16hp M&M that has only a 3 bolt hubs, it used to be my pulling tractor back when i did that. I have a 61 suburban with a 10hp engine with duals and a 3 bolt factory hub, never had a problem with it. The 3 bolt and the 5 bolt hubs are the same bolt pattern on most 12" wheels. I would just use what i had, its doubtful that it will be a problem.