preservenerd2017

I just graduated from Penn's HP program in May. I loved it. There were a few folks with similar backgrounds/interests to you in our cohort. One planned to attend law school after getting his M.S. - so an inverse pattern to yours. He applied to law schools in our second year and has matriculated at one for this fall. There was additionally a Penn law student who did a certificate in historic preservation as part of his law coursework, so he took certain required courses to gain a general understanding of the field (research/documentation, architectural history, preservation theory) to supplement his law degree. He has a job at a land use law firm currently. Another Penn law student took preservation law as an elective course and is now on the board of the Young Friends of the Preservation Alliance.
Considering you have a law degree, have passed the bar and have worked in museums and art organizations, I don't know if shelling out upwards of 50k per year for two years is worth it given your experience. (To be fair, a lot of folks get aid from Penn and I ended up with a ~50% scholarship, but it depends on the person and your background). A certificate program may be more useful for you -- so you understand the basics of what a preservation professional can do (Section 106, Tax Credits, NEPA, 4(f), etc.) without having to do a full blown courseload. But, I also understand that there are benefits to a full-time master's program.
I would also suggest getting in touch with the Young Friends of the Preservation Alliance to see how you can get involved with some of their work.
Feel free to message me directly - I also live in Philly! Would be glad to meet for covfefe or a drink sometime!