Welcome Aleks. Yes, acetone will ruin the paint and or plastic if not a metal model. Often by just handling a plastic model without a cloth or soft gloves wears off the script. I searched the DLE-90 ingredients, but they aren't disclosed. Could be citrus based. It isn't expensive, and both Modelbahn shope Lippe in Detmold Germany and Trukmo have it and ship to the US. If the shipping is more than the product or equal, I would order other items with it. Both sell Herpa, Wiking, Busch, vehicles, scenery, and Structure kits as well as trains, motors, decoders, etc.

Definitely give ELO a go - it usually works for me.
I often use a sharp curved blade which I use to gently and gradually scratch off the number or lettering.
I say curved because you dont want the point to take away any of the paintwork itself.
It isa little more precise if you need to get rid of only one figure in a long number.

ELO also can be used to assist bedding down the decal _ I am sure it is the same stuff as the old Champ Decalset if diluted somewhat.
Kimball