This tells me they are very old. Also, the mounting holes lay directly in line with the post and not off to the side. These tuners are the same that Gibson starting using on their EB-0 and other model basses starting in 1969 and ending sometime in the late 70s. The difference between these and the ones that came on the Gibson brand instruments was those had a Gibson logo. I believe they may be vintage aftermarket.They are 4 in a line. They will fit a Fender style headstock where all the tuners line up in a row.
They come with nuts but no washers. These are very hard to find.The item "Vintage Schaller M-4 Bass Guitar Tuners 4 inline" is in sale since Tuesday, August 30, 2016. This item is in the category "Musical Instruments & Gear\Guitars & Basses\Parts & Accessories\Guitar Parts\Tuning Pegs". The seller is "adformento" and is located in Los Angeles, California. This item can be shipped to United States, to Canada, to United Kingdom, DK, RO, SK, BG, CZ, FI, HU, LV, LT, MT, EE, to Australia, GR, PT, CY, SI, to Japan, to China, SE, KR, ID, to Taiwan, TH, to Belgium, to France, to Hong Kong, to Ireland, to Netherlands, PL, to Spain, to Italy, to Germany, to Austria, RU, IL, to Mexico, to New Zealand, PH, SG, to Switzerland, NO, SA, UA, AE, QA, KW, BH, HR, MY, CL, CO, CR, DO, PA, TT, GT, SV, HN, JM.