You will probably be able to find a permanent replacement turnbuckle soon enough. If you can't in New England, give up!
But for a jury rig, there are many other things you can do, limited only by the tools and materials available nearby or on hand.
You could get some flat steel bar, perhaps scrap stainless, make two pieces with holes in the ends; slack the opposing shroud and bolt this to the rigging eyes. Then tighten up the rig.
Similarly, you could use s short piece of chain between those quick links, selecting it so that a number of links can be selected that is close to the tightened turnbuckle length, and install as above.
Salvage a turnbuckle - is there a baby stay or some other rigging that is non-critical?