Torque GT have had the engine out of my car before. They aren’t dedicated NSX specialists (they deal with all types of JDM imports), and they don’t have Kaz’s depth of knowledge and expertise (who does?), but they are good guys and they are very experienced with 90s Hondas in general. I’d certainly trust them to investigate, and I believe general engine build work is within their capability.

If your engine does turn out to have suffered a major failure, it may be simpler/cheaper to replace the whole unit rather than strip and rebuild. Christian at ATR in Austria may have some spare used motors in stock.