The Montgomery County Commissioners are guaranteeing a $6.2 million Redevelopment Authority bond issue for the Studio Centre. That’s the new name for the old Logan Square Shopping Center at Markley Street and Johnson Highway in Norristown.  A movie production studio that gave birth to the new name is now out of the picture, but two anchor tenants including a Pathmark Supermarket and the North American headquarters of USM, a commercial building maintenance firm, have already signed leases.  The bond issue boosts county funding for the $80 million project to about $10 million.  The two anchor tenants should generate about 330 jobs.  Plans call for renovating the old sears store, and all other buildings on the site, and putting up a new parking garage.