Yes, orphan remotes CAN be coded to a different receiver. (Update: I've documented the process, in another post).
If you can locate a 14P receiver, there are generally a few on eBay, [MENTION=15821]Chase[/MENTION] Acura can get you new remotes coded to that receiver at ~$130 each.
Base part number prefix is 08E60 and 08E61 for the original 318mhz style receiver and transmitter. You do need the external eight-digit serial number on the receiver, though at least some units have a "Learn" feature. These units tend to be found on Legends, Vigors, and some Accords.
Honda and JDM used 08E50, 08E51, 08E52 likely with 433.4mhz remote. The keyless unit needs to have at least a 14 pin connector and some JDM units can have 30 pins (they appear otherwise identical to the 08E60/08E61 unit). Less than 14 pins or no serial number is a no go.
For those concours folks: the original keyless box is metal and generally has a SL0 or SP1 infix number, though Legend units were also fitted. Though other infix numbers should work as well as those with a plastic container. The Accord unit is 08e52-sm5-1000-01.
Do note that the receivers have the same capacitor leakage issues as other electronics in the NSX.
You can DIY a harness with the instructions provided in this thread:
http://www.nsxprime.com/forum/showthread.php/140311-91-92-Keyless-Solved
Some known fully qualified part numbers for an early NSX designated receivers, made by Kenwood:
Acura: 08E61-SL0-2000-02, 08E61-SP1-2000-02, 08E60-SL0-201F
Honda: 08E52-SL0-0000-01 (-01 is the receiver in this case),
I purchased a new keyless kit for my USDM 1991 from an Acura dealer in the early 2000's with 3x remotes, 08E61-SP1-2000-02. FYI, the transmitter part number is: 08E61-SP1-2000-01. The receiver and transmitters all had matching serial numbers. It was an NSX kit as the remote cases have "NSX" debossed on them, instead of the generic "Acura" deboss.
It should be noted that a functionally equivalent receiver could have different part numbers
08E60-SL0-0010-02 (JDM, made by Tokai Rika, unsure about remote availability)