Hey Don,
Count yourself in a very minor minority! Your clean battery box after 50 years is a reflection on your stewardship of your automobile. Unfortunately, you were the aberration and not the norm. There should have been more owners like you!
My 1958 was 3 years old when I got it, and the battery box had already rusted thru and eaten the carpet off the right side of the transmission tunnel. The PO probably never knew what hit him until it was too late. I didn't realize that the box could be replaced, so I cut up an old tire tube and lined the bottom half of the box with a double thickness of tube. Recently, on the website for new brass plates, I saw a photo of two plates that had been completely eaten off by a [probably] over-filled battery.
I can remember reading "buyer's guides" on TRs that always started with the battery box and sills.
I have a "no service" battery, which is all I will EVER have, after my - and others' - experiences. A car owner is conscientious enough to keep his battery filled with distilled water, but he is TOO conscientious, and overfills it, leading to all kinds of problems.
Lastly, thanks for the concours information. I may try a concours someday, after I have the "little things" taken care of. Which is insane, because when he gets finished with my rack and pinion steering, electronic ignition, Moto Lita steering wheel, dashboard turn-signal and fog light toggle switches, Monza exhaust, radio with antenna and rear seat speakers, 195 tires, 60-spoke wheels, etc, etc; my proper decals and brass plates aren't gonna matter a tinker's darn. I figure that with my proper decals on the air cleaners (2), oil filler cap (1), and brake/clutch reservoir (1), I may end up with the only 4-POINT Triumph in existence!!
Peace,
George