Wouldn’t it be easier to modify a bike trailer than start from scratch? I’ve no experience with this, but I’d presume one of the axle connector models might be fitted with some imaginary custom peg to account for the few inch height difference. Obviously trailers that connect up by a by seat would not work, but what about this sort of model?
or maybe just flip the post on a model like this? 
He’d tell you because I was crazy.
I’d say it was because he wanted us to both move in with his (wonderful and supportive) family.
I was crazy, but not THAT crazy.
We had been living far away from his family, but he’d landed a fantastic job in their home town. Before the move, his mother started calling me and telling me that if I wanted to live in her house, I’d have to be respectful, and not go out drinking all night and coming home drunk – something I’d never done or conceived of doing – or what chores I would have, or how loud I could be, and when we would eat, and so on. I told him that I could not live 24/7 with his mom. I said I was moving to MY mother’s and when he got us a place of our own, I would join him. He didn’t. We divorced.
The divorce was fairly amicable. That was all about 30 years ago and I never remarried. I did shack up with a wonderful man for about 20 years, but I eventually kicked him out because he’d shrink into the shadows when I most needed support and I was tired of feeling emotionally devastated when I reaching out for succor and instead finding a void. I explained that I’d rather know that no one is there to help if I’m flailing about than to have someone I trusted stand by and do nothing. Yeah, I’m bitter about that one. I still love the guy, but sheesh.
Yeah, they trend over $100, but I was thinking the wheels and all would end up costing almost as much. I know nothing about this companies and this is NOT a recommendation (cuz how would I know?) but here’s two random links (also, I added a pic to the initial post):