Option 1 - Send your slide out to have it cut. You can either have the cut fit the red dot of your choice or have it cut to a more generic footprint to use a adapter plate.
Option 2 - Scour the web for a V1.0 CORE slide (or slide kit). These were discontinued a few years ago and may be hard to find. They came in 5" or 4.25", as well as ported or non-ported for 9mm and .40S&W.
I bought the 5" Ported CORE kit for my 4.25" V1 M&P9 back when they were on sale. Topped it with an RMR. Came with the slide, barrel, plates, and suppressor height sights.
Bear in mind the CORE slides have a "generic" footprint and you need plates to mount a red dot.