You are pair of NOS Amperex ECC83 / 12AX7 Vacuum Tubes - Bugle Boy marking, Made in Holland. Tested strong and working on my Eico 667 tube tester, but don't have a better tester on hand.

Both date codes read: I61 (delta)91. According to the Tube Classics date code for Amperex/Phillips, this is a 1959 version of the ECC83/12AX7 "Early version of the I65 type". Apparently purchased (and stored) at the same time, but no idea if they are matched or not (aside from the same date code).

Some bits of minor green corrosion on the pins, and one box is a bit moth eaten. I have not tried these in an amplifier (NOS, never used and in the box since 1959.Pulled out for the first time to test and take the photos!!).