Simon start up currents are not accurate on either types of meters, they are too slow, so I would ignore that reading, the running current is the most important, but as you noticed the current dropped after a bit of lubrication, which is a good sign.
You mention that you have cleaned and lubricated "the bearing",..... single..... there must be two bearings surley, or have I missunderstood you?
If you can see the commutator, then yes... give it a clean, but just have a look between the comm` and the bearing, there might be a felt washer which should be saturated with oil before you box it up, this is a kind of resevoire for lubricating the bearing over time.
I dont know if you saw it them, but I did post some pics of oiling the bushes of my Atmo rear fan without removing the impeller and showing the felt washer, if its of interest, clearly its not the same fan, but the principal is the same. (page 5, half way down)