I've made a few, they are each suited to the relevant barrel nut as not all barrel nuts sit in the right place for the handguard without some modification. Some have a flat washer made, some like the previous pic are sleeved, others require the nut to be machined too.
I would offer to help, but...
Can't speak for that specific rail, but i've fitted various rails to NGRSs and usually it's pretty direct except needing a large "washer" to go inside the new barrel nut as NGRS barrels typically slip through AEG barrel nuts.