Well if you have access to all the Delrin or POM you need, I would fabricate some kind of sliding/locking mechanism and a bolt on adapter so you could use the existing binding holes. That would require some more design, but the whole package would become more packable.
edit: if you are feeling more adventurous, you could also simulate a ski boot adaptor and click the whole sled structure in the ski itself. Wouldn't that just be a machined plate with some POM in the front and back?
Well if you have access to all the Delrin or POM you need, I would fabricate some kind of sliding/locking mechanism and a bolt on adapter so you could use the existing binding holes. That would require some more design, but the whole package would become more packable.
edit: if you are feeling more adventurous, you could also simulate a ski boot adaptor and click the whole sled structure in the ski itself. Wouldn't that just be a machined plate with some POM in the front and back?