I found some original documentation inside the Grob band filer. I was also able to date the manufacture of the filer to May 6th, 1946. The Grob company was just up the road 25 miles north of Milwaukee in Grafton. I contacted my friend Jean at Grob to get info on the band filer as she had helped me with info on my bandsaw a few years back. Here's what she wrote about the filer:
I found the manufactured date of your filing machine, It was manufactured May 6, 1946. Now for the bad news. There is A VERY limited amount of parts for your machine. I am including a copy of
what file chains we have in inventory. We have some 1/2" heavy duty file chains which are indicated on the sheet by either NA (not available) or yes ( in stock). We no longer have the machines nor material to manufacture them anymore.
Here's what Jean sent about my bandsaw a few years ago:
Your NS-18 was built Jan. 24 1942 and yes you can still get some parts. Especially the guides, holders & rubber tires. I am attaching along with this e-mail a drawing for your saw. This is all we have available. If you have any further questions please call us at 1-800-225-6481.