I actually don’t want to use it for the chain lubrication, my plan is to use it for oil to mix with petrol on the petrol stations. So I don’t need the drippers.
The tank I have here is the later cylindrical shape. How did look the old types? I quess it’s fitting to long wheel base frames only.
I measured the screw, it’s 48 mm (slightly over 1 7/8 inches). I would be very happy to have original cap. In case you have 2 pieces, I would buy for my friends tank as well