I have a cutter with the oil stored in the handle, when pressure is applied the oil flows thru a valve onto the blade.
I use half and half engine oil and kerosene.
The blade is protected when not in use by a small length of garden hose pushed over the cuuter head.
The edges are removed with a whetstone commonly called a spit-stone, a carborundum disc about 75mm across and 15 mm thru.
Water is run on this and the glass as it is rubbed up and down the edge to have the sharp edge removed.To clean the glass, water and an aquarium scrub, followed by a hose down and leave standing up to airdry.
Do not store glass face to face, touching, when wet, in fact, store it with sheets of newspaper between, otherwise you may get what looks like an oil stain as you'd see if you put a drop on the surface of water, this imbeds into the glass and makes it useless foe a viewing pane.
Paint can be removed from the faces with either a razor blade or as I do it, with an off cut of glass.
Remember, the glass don't feel a thing as it slices thru your flesh, so take care and be prepared for the enevitable cuts you'll get; a flannel a bowl of water, cotton wool and some sticky plasters, and a darling wife.(or husband), you may not need the above, but better than trapsing a bleeding appendage thru the house to the med upboard.
As some one has said, practice practice practice.
Good luck, and you'll really get a sense of acheivement when you make your first, own tank. It'll be rough, but with experience you will improve..
You have to start somewhere.
Alan 104