A manual for the 27 can be found at
https://res.cloudinary.com/singer-se.../268_27_28.pdf and
https://ismacs.net/singer_sewing_mac...e-manuals.html has one for the 127-128 There is another manual at
https://www.manualslib.com/manual/12...Singer-27.html
The 27 has a spoon shape metal piece below the tension assembly. This predate the tension assemblies that had a pin in the center which released the tension when the presser foot was lifted. Therefore, one needs to press that metal piece to release the tension to remove the fabric.
I can't tell if it has a motor boss on it or not. Leon has some pictures of the motor boss at
Boss for Singer motor mount or hand crank pics
Janey - Neat people never make the exciting discoveries I do.
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