Bad news, I just drove through Mass Ave in Cambridge and it seems like most of the used record stores have closed down. I'm not exactly sure why all of a sudden with the resurgence in interest of vinyl, but last year around this time I walked that street and was basically seeing a different store on every block for miles! Talk about a feeding frenzy! I think one that looked like it was still open was Looney Tunes. You may want to google it.
Good Luck
Good Luck