They sell the marathon winters in 24x1.75" (not 2.35" or larger though). It looks like you can order it from the website directly:
https://www.schwalbetires.com/bike_t...arathon_winter

The Nokian M&G come in 24 x 1.9", they're officially listed on the website but not sure where to order them:
Tyres | Suomi Tyres

I suppose neither of those are 2.35" though.

If you want to make your own, I'd take a look at the stickied thread in this forum titled "Making Your Own Studded Tyres":
Making Your Own Studded Tyres