Welcome to the sickness Murph. I'm far from a "master" when it comes to the old DPs but I am a dedicated Craftsman nut and recently got bitten by the DP bug and now have 6 prewar Craftsman presses in my shop. My goal is to have one each of the pre-war Craftsman DPs. I'll weigh in on this best I can.
Your press was definitely made by Atlas. If the machine tag is still on there the model number should start with 101. I've attached a catalog clip from 1941 as it's the closest artist's depiction I can find to that press. The drawing is missing the flat oval spot on the front of the pulley cover but I think that's a shortcoming of the drawing. I've seen your press with the oval "Long C" logo plate there on that flat spot on several presses. A more common pulley cover found on the old Atlas models had "Craftsman" forged into the front of the cover.
What throws me on your press is the "Heritage" logo on the side. That logo wasn't used until after the war in 1945. During the war there were purchasing restrictions on power tools so there weren't many (if any) sold to anyone not involved in the war effort. The catalogs I have access to for 45 and 46 don't depict any DPs. There's a few depicted in the 47 catalog but they're King Seeley made models. The first "full" tool catalog after the war came out in 48, by then the King Seely 103 models had pushed out the Atlas presses.
Your press is the third I've seen with the Heritage logo on the side. My guess (and that's all it is, a guess), is that your press was manufactured prior to the war, but not sold (or even released to Sears). Following the war they had a stock of those presses, slapped the "new" Heritage logo on it and shipped them to Sears. Again, just speculation on my part to explain old press/new logo. Your press may have appeared in tool circulars or regional catalogs that I don't have or they may have only been sold in retail stores.
Re: the return spring. I've not had to deal with this so far but I will on one of the presses in my que. I read of a technique on the Vintage Woodworking site of stabbing that broken end through a raw potato (to use as a heat sink), heating the broken end and bending it to form the 90 degree bend required to go into the appropriate slot. I've not tried that but more than one contributor over there swears that's the way to go. If it works it'd beat hunting down another spring.
One question for you. Is your press gray? I can't really tell with the lighting in your pics. If gray, does it appear to be original or a user re-paint? From what I'm seeing as I scoop these presses up, Sears did away with the pre-war blue and went to Nazi-stomper gray during the war.
Keep us posted. I happy to hear you're saving a family heirloom!
thought I had some pics but I can't seem to find them at the moment.
