I'm not sure about the Designer 1+? I almost certain that the Designer came out after the 1+ and the fact that the interchangeable walking foot works on your machine verifies that to me. Mine is a computerized/embroidery machine but does not have the ports for connecting a computer to it. An attribute that came on newer models.
The 1+ came out in the Fall of 1994 and I was still working ~ had no clue how to sew/quilt. I convinced DH that we would be retiring and I 'needed' the best machine available while we still had disposable incomes. I do not regret buying this machine, it still amazes me what it can do, the fact that it is all metal construction and was still made in Sweden at that time. I guess the only achilles heel to this machine is as with all computerized machines the darn "Motherboard".
Thank-you EVERYONE for your input I'm feeling much better as I have to straight line a wall hanging border .... with curves around military patches on three of those corners which I think I can mark with disappearing ink to follow those lines.