The R47 has been many years in the making and is a small open source project which has collaborated with the Swiss manufacturer of calculators, SwissMicros. It has a superset of functions over older HP models and many more too, including complex solve, default 34 digit decimal precision, 1000 digit integers, graphing, extensive complex support, etc and is substantially customisable.
I have no affiliation with the project, but excited that there is a new RPN machine commercially available.