Locating open market Schrades seems to have pretty well passed. At least as for importance in a sticky. Perhaps a member can cut and paste a missive on carbon steel care. A composite from past posts maybe? I'll offer a bit here on the 33OT and carbon, but it is far from inclusive on care. More of pattern history and specifications.
The Schrade Old Timer 33OT Middleman Jack is the two blade version of the 34OT Middleman introduced in 1964. The 33OT first listed for $7.95 in 1976 and last MSRP was $30.45 in 2004. It has a closed length of 3 5/16" and weighs 1.7 ounces. The two blades, one medium clip 2 1/2" and one pen 1 3/4", are of 1095HC steel.
It's open stock ancestor was the 233 Jack Knife which continued production until 1979. It was introduced without a name, and given the fitting name Middleman Jack in 1981, it's size fitting between the smaller 108OT Stockman and the larger 8OT Senior Stockman.
I have a couple of 33OT and 34OT's. For general daily use, I love the carbon steel blades. Yes, they do rust if not cared for. A proper overall patina, cleaning and a good light oil (I use olive oil on mine) will keep them looking and functioning well.
As with any knife, proper sharpening care is essential to maintenance. A person can degrade a well made knife quite quickly by being overly agressive, not maintaining the chosen hone angle every time, or trying to get a fine edge with a coarse stone. I like to work up to the fine edge. You loose less blade material that way. I see knives five years old that look like forty year old knives, and I have one I have used and sharpened for thirty years that is full bladed and good for another thirty.
Codger