so you could also ask for enfield parts.
That would have been too easy...
I don't think that those 16" wheels were used on anything badged Royal Enfield.
yes , 16" wheels and more
longer swing arm , wider forks , fat fenders , big american gas tank ... american handlebars .
the main frame and engine are Enfield ... but the styling was pretty specific to
to a perceived American Market for the older Indian-style ( motorcycle cop bike )
less than a 1000 made , parts could be thin on the ground .
i hope you find the bits , it may take a wihile .