Hi, Marco. N5492 was a single gun ship with a simple leather butt pad on the gun without the windscreen. It had the standard small square access panel just forward of the intake pipes. It's hard to tell from photos whether it had a large or small tailplane. From February 1917 on, all Tripes came off the production line with the small tailplane and aircraft in service were retrofitted with them as they became available. In the photo of N5492 on page 70 of the Osprey book, Sopwith Triplane Aces of World War 1, the elevator appears to sweep outward and forward, indicating the older, large tailplane. Considering the service life of this particular bus, it's likely to have worn both at one time or another. I'm certainly no expert and hopefully someone with more information will chime in, but I hope this helps.
Cheers,
Bud