Mildred I'd say your exhaust gas analyser would've been made for Penske by the Peerless Corp. (It might be handy to know if you need spares for it) I had a Peerless exhaust gas analyser that had an identical sensor box, only the monitor was different.
I gave it away only a few weeks ago, as I haven't used it for years because I have a Bosch CompacTest oscilloscope, engine and 4 exhaust gas analyser these days. I picked it up cheap on the same emporium of the ether: ebay.
Mind you, there's absolutely bloody nothing compact about it! [:D]
"Keep calm, relax, focus on the problem & PULL THE BLOODY TRIGGER"
80'Triumph TR7, 73'Land Rover (Ford 351. V8),
'89 Ford Fairlane
'98 MG-F, 69'Ford F250.