If you look up bobbins online, they usually tell you which machines the bobbins are for. Here's one I found that includes the 401A:
http://www.sew4less.com/product/7022...for_model_info
If you go to the store, the back of the bobbin card will list those machines it is suitable for.
I believe the 401 is a slant shank machine, so your walking foot and all other feet need to be slant shanks.
Don't use the Howard's Feed-N-Wax until you have first cleaned the wood. It would be the last thing to use on the wood, to finish it off. It is made of beeswax and orange oil and leaves an amazing finish.