Monty,
There are several threads out there about mounting a Bushtec hitch/harness to a 14/15. I did one a couple of weeks ago about it, and you would do well to read that review at:
http://www.cvoharley.com/smf/index.php?topic=103168.0Yes, this is for a '15 RGU, but it will be very similar to your Limited.
Additionally, don't be surprised by the lack of support at Bushtec. Nobody knows for sure what's going on with them, but it generally seems to be bad. I think for the most part, we still believe for the in their products (for now), but their factory service/sales people act like they just don't care.
See this thread for more details on that:
http://www.cvoharley.com/smf/index.php?topic=103203.0As far as using an older hitch or harness on your new scoot, don't bet on it. I'd definitely get a new harness, but if Bushtec says a slightly older year's hitch would work on a 14/15, I'd take that with a grain of sand.
Sorry I can't be more help. PM me if you have other questions.