Nice Frame...so far...let's see the rest, you can't hold out like that!

I have the same fitting on a '50 Norman and an older brass sleeve and cap on a Hercules. I use 30W oil in the Hercules BB, half a dozen drops before a ride. It doesn't leak out, the bearings run silent, although I've never put more than 20 miles at a time on it.

Some early bicycles were lubed with oil, perhaps a little grease on the outer bearings to protect from water. You can still find Cyclists oil cans and kits on eBay from time to time. Not sure if the tecalumit port is for grease or oil?