You will need to get a filler rod to join the two of them (well, you may be able to get the brass to flow, but I woudl not recommend it).

I woudl assume the bushing you are using are actually bronze. Be cautious if they are "oilite" style. If so, they will be a less than 100% dense sintered product that s impregnated with oil or wax. If you heat it, the lubricant will be no more.