If you are after a gloss black finish that sticks like the proverbial s... to a blanket, and in a one step process try this stuff.
I will endeavour to get some. This looks to be the (almost) perfect product for doing this job with minimal fuss. I would prefer semi gloss , but I can always refinish it afterwards.
This will allow the molasses method
speedierecommends (no rust to covert - avoid grey primer that may show through in the future).