Sometime around 1877-1880 most W&G chain stitch machines were prefixed with the letter A though there was a B series as well (scalloped bases) and to add more confusion there was a later series (grey electric) with no letter like the first pre-1877 ones and the free-arm hat machines which had a letter S prefix.

Early rare Willcox & Gibbs 1870 model chain stitch machine

This is the pre 1875 model without automatic tensioner and no letter A prefix before the serial number.

What we are going to do here is concentrate on the letter A prefix models which make up the majority of post 1876/7 machines.

Willcox & Gibbs hat chains stitch model 200 series had an S letter prefix before the serial number

Willcox & Gibbs 200 free arm hat machine

Example of letter A prefix Willcox & Gibbs chain stitch sewing machine post 1875

Dating your Willcox & Gibbs sewing machine

To work out an approximate date of for the A series (only for machines with the letter A, Automatic, before the number) try this formula. This is by no means perfect but does work in many cases. You must pick the date which is between the two methods below.

Method A.

Take the number from the sewing machine above, ignore the A, (545351), minus 279638 from it. Divide by 17500. Answer, 15.1836. Ignore everything but the first two digits (15). Add this to 1877. 1877 + 15, bingo date...1892. 

Now using the Courtney Willis method of dating the Willcox & Gibbs sewing machines (with the A, Automatic prefix).

Method B.

Divide your serial number (in our instance A545351) by 8,000. Ignore the numbers after the decimal point and then add the first two numbers to 1838. The date for the our machine becomes 1906.

Finally.

Take the middle date from the two methods, 1906 and 1892. Approximate year of manufacture for the above machine becomes around 1900. Just a few years from correct.

By averaging the two dates in the middle, using both A + B methods, you may get close to your manufacturing date.

Here is a great invoice for a new W&G in 1911 with the serial number 578938 sent to me. By using method B we can date this machine to 1910, allowing for a period of time between manufacture and sale method B shows a perfect outcome.

I do hope that helps you work out a rough age of your little W&G machine.

If anyone out there has better records of the W&G machines or worked out a better dating system for the missing W&G dates please do let me know: alexsussex@aol.com

Fancy a funny story: Ena Wilf & the one-armed Machinist