My understanding, but only from memory, is Adler put together ISCs, there was a relationship between Adler and Victorinox and Mikov eventually took over the Adler line.
I have an ISC with Combo-opener put away for a rainy day which I bought from a company that bought up redundant/surplus Adler stock. I have mixed/repaired Victorinox with Adler parts. It was some time ago, but I think I came to the conclusion that mixing layers was fine, but not tools within a layer due to minor differences in tolerances. So, if you use an Adler or ISC Combo-opener, use the whole layer Combo-opener, blade and spring, although whatever the mix is you can test before peening.