Yes, some of the yards have transitioned from PNP to provided parts, especially out west (it seems). Some of the SoCal yards got tired of poor behavior and loss of saleable parts. The other two trends have been increased safety and environmental regs which "force" salvage yards to restrict access, and some states have such high insurance premiums that yards have just shifted away from PNP. LKQ has also been buying up yards at the cyclic rate, but to their credit, they are still mostly DIY, and the computerization of inventory has made checking parts and finding cars much easier (along with slightly higher prices). As for NE yards, I'm up that way monthly. I was back in the BRKs 2 weeks ago, but haven't visited Sam's since last year. Just check to see if yards are pick n pull- as said, LKQ yards are computer inventory, with pictures of each car (that's an easy way to find TDIs, too), but are still PNP. I think we had a discussion thread on yards in NE a year? ago, a search will prolly find it. It sounds like you'd prefer to avoid PNP anyway, which may make the parts-provided places better, and the computer inventories helpful. I think car-part.com is the one I see mentioned at Fred's the most. I don't use it that often, b/c the LKQ's in the mid-Atlantic are really good, and the yards provide cars I can practice on before touching my own, but it might be helpful if you only need a cover or bottom.
