Now, I don't own an industrial anything; but a friend of mine has a contract sewing company. He owns over 400 industrial machines, many are older vintage machines; and he has some older Huskvarnas. I wonder if there is a proprietary Huskvarna bobbin for your 27-20 or a more generic type such as an 'L' or an 'N' bobbin I have seen a number of times in his work area. He uses a lot of purchased, pre-wound generic bobbins for his work. I will ask him about your model to see if he has information.
John Thomas in NC