Re: ISO 512K blank programmable embroidery card for #1+ Viki
You can try emailing the owners here: http://www.tricosew.com/
I've been doing business with them for over 30 years. They have lots and lots of Viking products in the store and support some of the older discontinued models and/or may be able to tell you what can be substituted.
And ... that may be the case with other independent former Viking dealers closer to you as well. Viking, sadly under the VSM corporate ownership, has been yanking the licenses from the majority of the remaining independents here ... but I would imagine they still have plenty of Viking inventory to sell off. You won't find these former independents listed on the Viking dealer locator.