About not removing the inside cabinets - it’s often more work to work around things like that than it is to remove them.
Every camper or RV I’ve opened had more issues than previously thought, be mentally prepared for the rebuild to “snowball” a bit. If you’re like me you’ll find things that aren’t rotted but you’ll just be dissatisfied by how weak and spindly it’s built and you might wanna beef things up a bit while you’re in there.
If re-skinning the rig to eliminate the front window is an option, I’d strongly recommend also not drilling it full of holes for the marker lights. My next set will be LEDs held on with adhesive, with wiring in some sort of tubing. I might attach the lights to a strip of aluminum bar stock across the front, then attach that with double sided tape all the way across. Seems I could just attach a ground wire to that and only have to hide one wire, maybe behind the aluminum if the tape is thick enough to give clearance.