Weiss See --> David Wexler & Co. (Accordions & recorders ca 1940's to 90's)
Wilkinson’s Excelsior (Accordions & consertinas) See --> A. H. Wilkinson & Co. Ltd.
Wire Works (USA - guitar strings 80's) See --> Evetscorp
Woodstock Music Products Inc.
Yellowtools (Sample libraries, VST effects & instrument plugins) See --> Christian Hellinger und Drazen Vlahovic GbR
Zapp (Guitars) See --> Red Tree Music Inc
Zoller Guitars See --> Shadow Electronics of America Inc.
By 1905 he was opened up a general store in Þórshöfn and employed an unknown organ builder that was primarily there as a musical instrument repairer and tuner, dealing with pianos, reed organs other reed instruments such as accordions, but at the time reed organs were very common in Iceland not only in homes and public access houses but also as church organs, but they were invariably harmoniums (reed organs) with pipe organs not becoming common until the latter half of the 20th century.
However he also built new reed organs for the company even though the majority of the organs the firm sold continued to be imports, but it is impossible to judge how many were built in the end because the owner of the firm did in interviews and adverts appear to use the same word for building new instruments, for the assembly of instruments built from foreign knock-down kits and for major repairs of older instruments. So these locally built instruments may have been as few as 5 and as many as 25+ and the only example known appears to have no markings on it except for the name Harmonium.
3S See --> Suzuki Violin Co.
48th Street Custom Guitars
Initially the instruments from the workshop came either unmarked or in rare cases branded ESP or 48th street on the back of the headstock, depending on if the neck was a custom job or used ESP part but remember that until ESP bought Kiso Violin in 1985 the company was primarily a supplier of aftermarket and spare parts and not whole guitars or basses, this also meant that the bulk of the early instruments were copies of existing instruments, primarily Fender strats and p-basses since they were built from replacement parts intended for those models. Later in the 80’s 48th Street started marking their creations better either on the back or front of the headstock and also started utilising parts intended for ESP guitars more and more leading to instruments that look less like American classics and show more individuality, in addition they stared modifying and custom building ESP branded guitars and they also started selling guitars from Sunset Custom Guitars and in a few cases appear to have used parts intended for Sunset for their own creations, but we have seen 2 custom Stratocaster lookalikes built by 48th around 1990 that feature headstocks with the Sunset Custom Guitars logo.
Note that on early instruments built by the company there are often no visible markings to be found at all, by taking the neck from the body you will find ESP markings on the base of the neck and luthier scribbling’s in lead pencil on the body, typically NY and some undecipherable kanji characters (Japanese builders remember). The Company was closed down around the turn of the century as Schecter Guitar Research took over the role of supplying the USA with custom guitars and the retail store was sold to Sam Ash Music, the mother company of Samson Audio.