Transistors that replaced Nuvistors

My Tektronix 453 seems to have a problem on it's sweep generator board. I have checked all of the transistors on it, and most seem okay but two. These two were nuvistors (8393) in an earlier version of the 453, as indicated by the manual. The serial number is 41351. My manual has corrections going up to SN 13820.

But these two transistors have different part numbers and I cannot cross them with a modern number.

The transistors are Q533, with a "6937 1511005 " stamp, and Q443, with a "6952 1511005 " stamp.

The transistors may be okay, but for each one, I get very different B-E and B-C readings at a given charge polarity.

Any ideas?