I concur with this.
I would lightly sand with 400 grit, clean very well with wax/grease remover, then tack cloths, and then apply an enamel clear coat. Many brands are available. You can roll/brush it on, use those glass containers that some with aerosol charges and use the canned clear coat in those to spray it, or use the clear coat that already comes in spray cans. I would use 2 coats, not sanding or cleaning between coats and select a high gloss if u really want it shiny. I've used this method myself on my boat with excellent results. Hope this helps!
It's been along time since i had to think about paints. (went to college for Auto refinishing) I believe the only thing you can use over this paint would be another clear that is of the same type.
It sounds like you have an enamel with no hardner; so, that would rule out any type of polyurethane or urethanes or hardened enamels. If you do go over it with something that is "harder" than it will crack most likely and not adhere properly.
If you can find the same brand as the original that would be best. Brand mixing at times can spell disaster. if nothing else go right to a paint specialist and they will give you a very good recommendation. I would recommend this anyway.
Since appears to be glorified house paint i believe it can't be waxed either.
Most modern paints are parts of what manufacturers like to call “protective coating systems,” which include compatible fillers, putties, fairing compounds, thinners, and undercoats.If you’re planning anything more than a touch-up, ask for the full manufacturer’s directions because, all too often, one kind of paint will not stick to another’s undercoat, even if it’s made by the same manufacturer.Marine paints can be divided into two groups: topside paints and bottom paints.There are at least four major kinds of topside paint used on boats, each with its own characteristics and applications:Alkyd enamel. Marine alkyd enamels are nothing more than formulations of oil-based exterior house paint. On boats, this type of paint is great for interior spaces and makes an inexpensive deck paint. Thirty years ago, alkyd enamel was also the leading choice for topside paint, and it still does the job. But for a fiberglass hull, which—unlike a wooden hull with its constant working—provides a stable platform for a long-lasting paint, polyurethane provides a longer life and a higher gloss.Single-part polyurethane. This is a urethane-modified alkyd enamel, a compromise between alkyd enamel and true polyurethane, which offers good gloss, three- to five-season longevity, and moderate ease of application.Two-part linear polyurethane (LPU). This is the best choice for high gloss and a long life, but it’s a problem to apply. A professional polyurethane job is sprayed—not recommended for the amateur even if wearing the requisite respirator. Several brands are formulated for application with roller and brush; done correctly, the result is almost indistinguishable from a spray coating. Ideally, it’s a two-person job: one to roll on the paint with vertical strokes, the other following behind with a paintbrush to tip the paint with horizontal strokes. As always with marine coatings, preparation is the key to success. The primer will be proprietary to the topcoat.Epoxy. Epoxy is sometimes used as a primer over porous or crazed gelcoat under a topcoat of marine alkyd enamel, but its high susceptibility to ultraviolet degradation renders it unsuitable as a topcoat.Bottom paints are mostly antifouling paints; that is, they contain a compound to deter or prevent the growth of marine organisms, such as weed and barnacles, that would slow the progress of a boat or damage the hull surface. There are at least four common types of bottom paint: ablative, sloughing, modified epoxy, and vinyl, all of which usually contain a copper biocide. Teflon paint has no biocidal properties, and is used on racing craft removed from the water after use. Bottom paints may be incompatible, too, so you must find out what type of paint is on your boat’s bottom before you paint over it