A simple way to compile the "reverse list" of all RIR records that map all assigned IP addresses to the names of the organisations that were allocated or assigned these addresses by an RIR is to extracting the reg-id values and perform a whois lookup on any of the number objects listed in this stats file with that reg-id value, extract the organisation name attribute of the whois response.
I've scripted a process to perform this reverse mapping to run every 24 hours, and the combined extended daily statistics report can be found at:
https://www.potaroo.net/bgp/stats/nro/delegated-nro-extended-org
The format used in this report is to append the organisation name as an additional field appended to each record of an assigned number resource, where the organisation names used in this report are the names recorded in the RIRs' databases.
