Check Dave's cycle supply. They have a platform for 1100s for $140.
I ought my Markland from a cycle salvage yard for $75, so 140 for new is not out of line
My first hitch was very simple.
It went into the holes that the rear hoop goes in and replaces it.It then used two flat brackets that went to the saddle bag mounts betrween the bag and bar.
Was very easy to install,and would be easy to duplicate.
I replaced it with a markland light bar w/hitch some years ago and sold it for 25.00 to another member.Sorry