You could use a rod slightly smaller than the hole as a double check, I just check the spline / valley positions. Use the drift to get the insertion depth right, the tap the roll pin in, paying attention in case it hangs up.
I disabled, cleaned and re greased a clicky axle or 2. I also bought ball bearing balls, and replaced the bad ones in one. Look at the wear on the center start piece, and the walls of the cup. One of mine had a little more wear on the sides that were carrying the load, so I swapped the axle to the other side, which puts the load on the opposite faces. So far, so good. Almost all of my axles are OEM axles. I've been running these models since 1988. I bought used OEM axles back then and re greased them. When one of my earlier cars was done [due to rust] I saved all the parts except the rusted out body. I never bought an aftermarket axle, the only few of those I have came on the later used cars I bought.