Another one you might want to try is POR15 Engine Enamel. Specifically, "MG Maroon". I bought a can of it and the colour is pretty close.
The POR15 products are a bit pricey but you get what you pay for. This one is $22 for a pint can. You CAN thin it and spray it but I used a brush and it levels out very nicely as it dries. If you want to do the job "right", they sell a complete kit for $54.50 that includes solvent, degreaser, "prep & ready", a can of POR15 rust paint for the primer, the colour of your choice for the top coat, brushes, gloves and a face mask. This will - from my own experience - do a "forever" job on your engine.
If you've never tried the POR15 rust paint, I have to say the stuff is unbelievable. It's almost bulletproof when it dries. I suspect it's a single stage epoxy paint that cures with the moisture in the air. I've tried a lot of so-called "Rust Paints" (Tremclad, Rustoleum, etc.) and never found anything that truly stopped metal from rusting until I tried the POR15.
The stuff IS expensive. But I suppose if it protects what you put it on, it's worth it. I've already done the inside of the doors on my Manhattan, and I've done part of the floors on the inside.
Downside (other than price) is that once it dries, it's a very NON porous surface. Meaning, other paint won't stick to it. You have to either apply your desired colour before the POR15 hardens, or, use an etching primer (after light sanding) to get other colours on top. I'm using it on internal areas that are not seen so it doesn't matter.
Another thing, if you use it and get it on your hands, remove it immediately with solvent. (Acetone works best for me.) If you don't get it off while it's wet, you WON'T get it off. It takes about two to three weeks to wear off your hands. (Spoken from experience.) Also, when you put the lid back on the can, put a piece of saran wrap (plastic film) on the opening first, then put the lid on and tap it down with a mallet. If you don't put the film in between the lid and the can, you will not be removing the lid again. Ever..... (Also spoken from experience.)
Rick