The store is called Pleasant Valley. It's just off 472 (less than a mile) on Sproul Rd. heading east. Sproul Rd is just about 1/2 way between Quarryville and Rt 1 on 472. If you are heading towards Quarryville, Sproul will be about a mile past a BIG brick church on the right.
I'd be really surprised if they didn't have pickling lime. And I'm sure if they don't, they'll know somewhere that will.
My next try would be Kaufmann's on Rt 340, but that's a bit more of a haul.
If that don't get you there, let me know. I'll get better directions.
Oh, yeah. If you feel like you're pulling into someones driveway, it's because you are. And park in the parking spaces, not @ the hitching post.