I was just looking at brushes on a Marx #999 last night, as I was trying to replace a driver with a damaged rod connection, and wondering about that. I guessed Grossman, but wonder if he is having Marx brushes remanufactured? Early #999's have a pad to retain lubrication between brush retaining springs, but two parts engines, that I think are later versions, do not have that pad, or the retainer for it...first time I'd noticed that.