Just an afterthought;
If you are seriously going to do this I'd advise buying a cheap-as-you-can-find throwaway copy to practice your relic-ing on first.
The paint will not react in quite the same manner but at least you can try out your ideas on the hardware and attempt something on the finish.
At least in this fashion you won't completely ruin your Les Paul in the short-term...
BTW; Tom Murphy ages his limited run instruments largely through painstaking and time-consuming use of a craft-knife blade.