I am also looking for a baseplate 51156-06. Anyone else have one or know a place I can purchase? These things are like finding unicorns.
Welcome to the forum and to the fascinating game of detective-archeology-VRSCR accessories finding quest!
For me, the "R" is undoubtedly the best handling, performing, balanced, complete and reliable, (semi) mass produced Harley to date. (let's see how the new Revo-Max goes... hopefully won't as the Boeing 737-MAX did, LOL!!!), BUTTTTT, you'll need TONS of patience, dedication (or Money) to accessorize yours to your own taste and preferences.
Eventually you'll get almost every part you may need either on eBay or in this very helpful forum (I can suggest visiting eBay sites in Europe and/or UK as the Street rod was much more popular overseas and not everyone post their parts globally)
If you can't wait and may be willing to pay double or triple the original price for unicorn parts, you can go to
Jan Willem Boon - Obsolete New Old Stock parts for your Harley-Davidson motorcycle and American made replacement parts This guy bought I think all the remaining HD obsolete parts inventory and literally you can find there almost everything you can't find around the world.
The catch? beside the over, over, over inflated pricing, the guy WON'T ship outside Europe, so you may pay him in Euros, get a Friend to receive the part for you in the EU and then make it go to your door via Fedex, DHL or any other courrier, with the added shipping/taxes costs. I had to go though this for my engine guard, so I can tell the story first hand.
The baseplate isn't really a Unicorn to be honest. You have hope, don't despair!...Isn't any easy to find but eventually will pop up, but the engine guard???? that's not just a unicorn, it is a golden genetically engineered, mars born and raised, luminescent Chernobyl survivor hybrid of a Unicorn and a Tasmanian devil!!!!!
You can suscribe to one of the many Facebook V-rod owners group and the market place. I found a couple of rare accessories there and usually people is very reasonable about pricing there.
Good luck and enjoy your ride!