If you can afford it and find a decent plater, I definitely recommend Meerkat67's option, nothing beats the real thing.
Thank said, the material you've made the helmet out of might be the base cause of Molotow giving the results it has for you. I have not needed a base coat of paint for any of mine, I have simply needed it to be as smooth as possible. Molotow has actual metal particles in it that self level to give it that mirrored effect.
Several questions come to mind along that route:
Q - How smooth is the surface before using the Molotow?
A - The surface needs to be glasslike smooth for best mirrored effect, color doesn't matter. If it's not super smooth, you'll still get a nice Chrome look, it just won't have that crystal clear mirrored look (the reflected shapes will be fuzzy).
Q - Are you using a paint brush, airbrush, or HVLP paint gun
A - Brushes are fine for small pieces the size of your fingernails, or slightly bigger. Airbrushes are good for things about the size of your fist or long skinny items that only need that first pass. Anything bigger requires a small to large paint gun with a wide spray nozzle. The Molotow is alcohol based and dries so quickly that a second pass will give overspray that flash dries the alcohol giving it the foggy look. *small side note, because it's alcohol based, you can add IPA to it and nearly double the amount of Molotow paint, but it dries even faster when you do this
Q - How long do you let the Molotow set before you touch it, let along add top coats
A - I typically let mine sit for 24-48 hours before I even move it. If time allows, I will let it sit for 5 days under a bowl to keep dust away from it while it cures. At the end of that curing time, I then do the Aqua gloss as a mid coat (the mirrored effect does get foggy during this stage), and then once that is dried to a degree, I use the 2k clear coat to seal it and bring back the shine.
Here is the 2k I use and ordered off Amazon and when properly sprayed and cured, it has a glass like smoothness to it (that "wet" look you are looking for)
Finish 2k Clear Coat
Out of habit, I do use a high gloss base coat one items that are small with details I can't sand completely smooth. Here is the high gloss brand that I use as a base coat, before applying my Molotow
High gloss base for Molotow