I painted a rad witih hammerite radiator paint and it was difficult and awkward to work with and ran even with thin coats.
I rubbed it down today *not fun* and went to b&q and as suggested in other posts use satin gloss. I asked about this and was told by 2 of the paint bods no such product exists it either satin paint or gloss paint.
So I opted for a mid sheed non drip crown pure brilliant white paint as it was all I could see that would fit the bill, b&q had a homebrand of it, and a dulux one and a crown one. te dulix and crown were identical other than the crown was non drip so guess its thicker. SO 2 coats of that should be the ticket.
I'm just wondering what you paint you rads with and what results of the OEM look are like ?