How much grease in 1928 GB-W rear axle?

I'm using a rear axle from a 1928 GB-W sedan for my Indy car project. This is the same unit the factory used, has a 3.31:1 ratio, p/n 150040. I pressed on the bearings with the tapered inner race today. The bearing manufacturer's instructions said to push it on the shaft taper about .016-.020" axially to get the i.d to expand about .0015". It all went well - mostly. I was surprised how little force it took on my hydraulic press to push the bearing race in. After shaft installation, there is supposed to be .001-.005" play in-out on the axle shafts. I don't have that, so I'll have to make some new .005" thick hex-shaped shims to let the cups move out a bit. I'm not willing to push the inner races of the bearings farther up the shafts and risk reducing the roller clearances too much. I bought a roll of .005" thick x 6" wide x 100" long shim stock today, will have the local laser cutting shop cut me some new shims. Anyone else need shims for these axles, shim p/n 150028/150029? I'll make a few extras. I can also make the felt seals for the inner and outer grease seals, since I made some dies to cut them from F1 felt.

So, now I'm just about ready to button things up. The bearings are all greased, but I'm not sure how much additional grease to pack in the ends of the axle housing. There are two grease "injectors" located on the outer ends of the axle housings, so it's easy enough to add more grease over time, except I can't tell how much is in there already. If I put too much grease in, it will ooze out the felt seals onto the brakes. If I use too little, the bearings may run dry and burn out - not good. Beyond rubbing grease into all the rollers and coating things generously, how much extra grease should be inside the axle housing? Short of pulling apart the axle, how do I know when to add more grease?

Quite the pickle isn't it? I just give mine two squirts with the grease gun once a year and hope for the best. I suspect that since these bearings are pretty well protected from dirt it does not take a lot of grease to keep them happy. After all where is the old grease going to go?

Nathan