Is it even possible to remove paint drips from glass?

[Devora]

Some of these are historic - they've lived here longer than us (5 years). A few I added myself through inept use of masking tape during midnight paintathons.

Is it scrape away with a sharp knife, or accept the inevitable?

A scraper blade should do it

Use a window scraper like this
www.amazon.co.uk/Stanley-593Oc-Window-Scraper-590/dp/B0001IWDBK/ref=pd_cp_diy_2

Ah yes, that does look better than the bread knife I was considering

Huge thanks, already ordered.