If there is excessive wear between the arms and the shafts, the oil will leak out between the sides of the arms rather than making it up through the holes in the top of the arms. Realize that you are observing oil flow at idle. The oil pump will increase flow as RPMs increase. With this increased RPMs, you will likely have oil flow through the holes at the top of the arms. The question you need to ask yourself is, do you want to rebuild the engine to as new condition, or drive it for a while and rebuild at a future date? You will need to spend some money on the rocker arms and shafts eventually, and it is likely that there are other well-worn parts lurking inside. If it runs fine, I would drive it and get the rest of the good miles left in it.
Carl
