If you don't mind driving maybe the Simeone Foundation. It would be about an hour to 1.5 hour drive from Allentown. The museum is about 10 minutes from the Philadelphia airport.
Simeone Foundation Automotive Museum » Home
He has a 917 and a daytona coupe in there.
If you are into modern furniture you could check out Knoll's Museum in East Greenville, PA:
http://www.knoll.com/museum/index.jsp
Two other places I'd check out if:
1. Leydon Restorations
http://www.leydonrestorations.com/
If you give them a call you might be able to check out their facilities. I've seen some of their machine work and it is something to behold. It is kinda sorta on the way between Allentown and Newark.
2. DL George
http://www.dlgeorgecoachworksltd.com/Links/Links.htm
Another Restoration shop. I don't know if they give tours or not, I've gone for a tech session with the vintage SCCA and that place has some awesome cars. They had a buggati atlantic the last time I was there.