This has not been added to for a while and it's a great thread.
I built this Logging Arch and I use it for a carriage as well. Works awesome. I now have a bigger heavy duty front wheel that works and looks way better. I will use a pole for a team and the front wheel just drops off. I have it so the shafts and poles can change very easy. I have a trailer hitch at the rear for implements or trailer. For logs I have a bar with some chain hooks.
Sent this out for Thanks Giving Card