I'm only "guessing" but I'm thinking a lot of those type of accessories are not going to work on the 301 because it does not zigzag. Because I don't know for sure I will only buy off of ebay things that specify for a 301.
Of course NOW I have a 500A and a 503A so I can buy for those machines :).
I'm kind of bummed because my local sewing machine store that I bought my Brother from a few years ago has apparantly moved or closed. I had decided to take my machines 1 or 2 at a time over there for a service call. I'm to impatient to figure out the WHY's of things not working correctly...lol