- Found adding machine.
- Fixed adding machine.
It was $2 at the local thrift shop. Being a sucker for old mechanical junk, I had to have it. At two bucks, even if it just provided a single afternoon's entertainment it was worth the investment.
For reference, it's a Sears Model 158.58010 manual adder. It's capable of adding and subtracting numbers with two decimal places of precision in a range between 0 and 9,999,999.99. Going under 0 will cause an underflow. It can also hold your current number with the 'R' key for repeating values (the '66 Sears catalog advertises this as "multiplication" which... sort of, technically), clear numbers currently in the variable register with the 'C' key, print subtotal lines with the 'S' key (prints out the current total with an 'S' next to it, retains total amount in the result register) and grand total lines with the 'T' key (prints the total with a 'T' next to it, clears the result register.)
The only documentation I could find on it were the advertisements in the 1965 and 1966 Sears catalogs:
It was the more expensive of two models at $69.65 in 1965 (about $660 adjusted). The price was slightly dropped to $66.88 in '66. The cheaper model omitted subtraction and only operated up to 999,999.99. The catalog number was 3 A 5801N.
Mine arrived to me with a damaged paper bail, a non-functioning paper advance, and a non-functioning ribbon advance. I fixed the ribbon advance by taking it apart, cleaning it with gun cleaner, and applying gun oil for lubrication (this is my go-to for anything mechanically complex like typewriters and adders; it seems to work well enough now that "typewriter oil" is no longer a thing.) I fixed the paper advance by applying a very thin layer of silicone gasket maker to the rubber rollers and allowing it to dry. For good measure, I cleaned and re-lubricated the rest of the machine as well. There's nothing to be done about the paper bail, so it remains damaged. It also appears to have originally come with a top case, which mine is missing.
To its credit nothing inside has rusted, and it all appeared to be in remarkably good shape. After a few operations, everything except the issues listed above worked great. It seems to have been a very well built machine. Everything inside is solid metal.
And of course, like everything of the era it has double shot keys:
It also appears to be a near internet virgin. Aside from that catalog page, it looks like this adder has only ever been mentioned one other time on the web. One was potentially listed on shopgoodwill a year ago, but the pictures don't work anymore so I can't verify that. Otherwise it seems to be a pretty rare model. It would've been the very tail end of manual adding machines for sure. They were no longer being advertised by 1967.
I wanted to quickly write it up here so there's some record of it that comes up if anyone ever googles one again.
But yeah, that's what I did today.
Edit: Fixed one detail. I assumed the adder was capable of negative numbers, but it's not.
