Well back in the days that martis had tubes in them, they were in a box that stood nearly 7" tall. When they switched to solid state, the chassis stayed about the same. That was the RPT-25, which was made until approximately 1985 or 86.
When the RPT30 came out, it was in a chassis that was about 3" tall, rack-mountable in two rack spaces. And it was beige-ish, the same color that the RPT-25s had been for many years.
At some point, they started making them a charcoal color. That was my question, and I was hoping someone would know off the top of their head. I think I'll check those power supply caps. (Good suggestion)
Of course, I could also call BE and give them the serial number...