Yeah I was in my commercial SW store the day after I posted and ask my sales rep about the DTM Alkyd. He had great things to say about it. I ask him why he never recommended it to me and his immediate response was "7 day cure", (I'm not very patient).
As far as a recommendation for future projects SW BondPlex is a great product. It is water based and a much better product than DTM Acrylic which is what I thought you originally used (I have no experience with the DTM Alkyd so can't comment). Not sure on the cure time but it is waterbased (so fumes won't be nearly as bad as the alkyd) and dries quickly. Another bonus is you won't have to worry about temperature as much with it and based on the pictures that crappy little shop you have probably doesn't have heat. Just kidding, but seriously you mentioned cutting firewood so I would assume you have cold temps arriving which poses two problems with the alkyd 1. Depending on how your shop is heated, if you spray inside you could blow yourself up from the fumes being ignited by a pilot light or something (it does happen) 2. The cold temps will cause your cure time to double, triple, or just make you want to shoot something.
The other option you have (and I wish I would have gone with my gut and used this on my trailer instead of Monstaliner) is SW SherKem. (I ONLY RECOMMEND THIS PRODUCT IF YOU HAVE A RESPIRATOR AND GOOD VENTILATION). Obviously with that warning this is not water based. I have used this many times on many different things (several enclosed trailers, a box truck, industrial applications, etc.) and it is amazing. Extremely durable. Holds color and sheen like crazy. It's what companies like John Deere use on there implement equipment. You can recoat it in 15-20 mins (but before 2 hrs) and full cure in 24 hours. Two warnings: 1. It is a very "hot" product so if you are repainting something do a test spot to make sure the existing paint can handle it, otherwise it will wrinkle or won't properly bond. 2. High gloss is super shiny, like looking in a mirror, it will probably have more shine than your tow vehicle.
On another note, you mentioned having a local shop skin the trailer for you. Based on the work you have done on your trailer I would think you are more than capable.