At 6 weeks old it's most likely not a shed. The guy you bought him from is also either a liar or an idiot or both. A four week old Borneo would just be taking his first meals and I doubt he took 3 mice at once. It sounds like he sold you a snake that hadn't eaten at all. So here's what to do.
Get it out of the 10 gallon and into a shoebox size tub. Temps at 80. Higher temps turn hatchlings off and troublesome ones will feed more readily at the lower end.
Hides. A simple deli cup with a hole is great, shredded paper and At this age you can still keep him on semi-damp sphagnum until he feeds. This will keep dryness at bay and it will provide security. They want tight secure spaces.
Keep him like this for a few days, no handling then offer a live rat pup or hopper mouse. Offer at night when quiet, lights out, no other activity.
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