It’s a warbird. A WWII warbird. the aviation community doesn’t follow sorority rules like that.
And if it did, a state of war legally existed with Japan until the peace treaty was signed in 1951.
The original patrol bomber concept was considered obsolete by this time, and the Mars was converted into a transport aircraft designated the XPB2M-1R. The Navy was satisfied with the performance, and ordered 20 of the modified JRM-1 Mars. The first, named Hawaii Mars, was delivered in June 1945, but with the end of World War II the Navy scaled back their order, buying only the five aircraft which were then on the production line.
https://en.m.wikipedia.org/wiki/Martin_JRM_Mars
You can take a non-warbird and dress it up to look like one, but its just not the same as a legitimate warbird with a record of flyng missions in theater. I’ve been doing restorations for close to 40 years. For people like you who just go by looks, it probably doesn’t matter, but when you pay for one, there is a huge difference in price when you pay for an aircraft with a mission record. Plus there can be considerable cost involved in backdating aircraft to appear as it would in theater.