Your safest bet is to buy all your paint from one supplier. There are alkyd enamels, acrylic enamels, acrylic urethane enamels etc. If I’m not mistaken "enamel" just means it is a hard finish like the enamel in your teeth.
Self etching primer for aluminum is a good first coat. you can get it in rattle cans from the auto parts store. with etching primers, you don’t want to get it on too thick. a thin even coat is preferable.
I have access to industrial coatings in my line of work (shipyard) so I use an epoxy primer with aluminum, and or bronze powder as the binder.The aluminum primer is a nice dull aluminum that can be left as is. As Lloyd said, I wouldn’t use naphtha as a degrease. Use simple green to get the majority of the oils off,then follow up with lacquer thinner or acetone, or brake cleaner in an arerosol can, as a final rinse. Then paint immediately after the final cleanup as aluminum oxides re form on the surface very quickly after you clean them off.
Here’s a ’54 cowling with the aluminum epoxy primer sprayed on using a turbine hvlp paint sprayer. Had to thin it out about 30 % to get it to lay down.
Here’s a tank with the bronze primer
