Such Timing!
Today, after I hit Big Lots for some of that mystery Bold powder, I moseyed on over to the other end of the parking lot and checked out Savers for the first time in a few months.
In with some decorative glassware and vases I spotted a complete vintage Osterizer carafe, the early type with the flat lid, no handle, and smooth-sided metal blade assembly cap. I don't have a blender old enough to use that type, and at $14.99 I wouldn't have bought it anyway, but it was apparently an omen.
In the cookware section, I came upon a Presto model C401B (Keven, was that a typo in your OP?) stainless 4-quart cooker, complete except for the rack. For $5.99 I grabbed it. I found a couple of other things to take home, but the Presto was the main score. Along with model info of C401B, the last bit of information reads "cooker 409A." The handles are brown bakelite/plastic and the top one has a short list of cooking times. The safety plug is the pin type.
It needed some cleaning, but wasn't in bad shape, although it had seen use for sure. The beauty of stainless steel! When washing the lid, I noticed when I turned it upside down, it didn't drain through the vent tube. I couldn't blow through it either, but attempting to caused a tiny white ball to appear near the top of the tube. I pushed it out with a toothpick and then all was clear.
I think maybe this is the reason the cooker ended up at Savers. The gasket had partially melted and left residue on the top of the pot as well as inside the lid. I scrubbed all of that out and washed the gasket. I also de-scuzzed the regulator so it rocked freely atop the tube. I tested the cooker with some water and a dash of vinegar. It pressurized quickly, but one section of the gasket didn't want to seal completely. It might seal eventually, but it's time for a replacement gasket.
I checked on line and it appears the original gasket for this model (and others) was part number 33020, but that has since been replaced by 09906. I'm on the verge of ordering the 09906 but would appreciate confirmation from Keven or others familiar with this model.
I'm looking forward to trying this cooker, and will keep in mind that it doesn't have the copper bottom if there's any browning involved.