Bernina Industrial circa 1940. Bernina started making industrial machines early on in their Swiss factory and although they are not uncommon this is one of the very early zig-zag models which is extremely rare today.
Cleaning your serger in a breeze! And cleaning sewing machine tutorial too! Please don't judge me for the dirt you're going to see, I've let them get dirtier than usual, but only for teaching purposes :) On SergerPepper.com
Complete Handbook of Sewing Machine Repair: Amazon.co.uk: H HUTCHISON: Books (OOP Vintage book - should be good for all-metal vintage machines :)!) ***I found a PDF version for sale here http://sewingonline.co.uk/repair-manuals.html for £4.95***
Textile art courses - British textile artist Chris Gray is a contemporary textile designer, artist and embroiderer who teaches wonderful sewing crafts for more textile art ideas visit http://www.mabonarts.co.uk