Johnson & Starley Heater fan bearing replacement?

I have a J & S J25/32 heater in the house. Over the years I've had to replace the fan assembly a few times as the bearings have seized up, squealing badly before finally giving up. This is no joke at around £200 a time, and all for the lack of any oiler point to the bearing.
I've just installed another today but am considering refurbishment of the old one for future use.
Is it possible to remove the bearing and replace it, maybe someone knows a northeast (Durham area) company who can do this.
Also, since the bearing has an end cap to it which has no lubrication point, can it be drilled for a small oil hole to be used for occasionally lubricating the bearing, and if so what grade oil should be used.