Yes, this is what I would like to know. Keeping the front and backstays as they are and relocating the uppers and lowers to the outside. I've seen it done on a Pacific Seacraft, and was wondering if it had ever been done to an Ericson.
You should also consider the basic rigging design changes that appeared in the (late) 70's and into the 80's. Earlier (and proportionately narrower) fiberglass boats, including Ericson's, had chainplates glassed into the hull layup until the wider designs in the 80's rewarded having the shroud bases inboard and tied to internal grids and rods. And to bulkheads. This allowed closer jib sheeting angles.
Another difficulty, due basically to aging, is that the shroud chainplates that were embedded into the hull layup had no way to inspect them for cracks or corrosion without removal and expensive re-glassing of new ones.
On the older (chainplates out next to the deck edge) designs, from EY and a host of other builders, it often makes more economic sense to establish new external chainplates and just use the buried ones as backing plates. The sheeting angle changes, but not very much.
The rig geometry on the 80's King designs is wrong for forcing the headsail sheeting all the way outboard by changing the shroud bases.
You did not mention it, but one other reason sailors quickly got to liking having the shroud bases located inward close or beside the cabin side was safety and ease of traversing the side decks.
Such a change would required new spreaders. Also the need for an evaluation by an NA. This might also affect the insurability. Remember that your hull, keel, and rig were designed as a functional entity.
Pointing.... the hull and fins of many of the PSC designs would not reward the movement/placement inward of the shroud base, IMHO. The very efficient keels of the Ericson's does, a lot.
"Your boat, your rules" as the saying goes, but an obvious rig change in that generation of the Ericson's would likely reduce the resale value to near-zero. Yup, that's an opinion.