Inks Lake is out near Burnet, which is around 50mi from my house in Round Rock. I went to one of their campouts but, I had already comitted to something else. I brought the tear down for the afternoon and chatted with everyone.
Just go up there (with or without your new/old trailer) and have fun. When you get to the gate, tell the ranger that you aren't camping (unless you really are) and that you brought your trailer for show and tell.