On Monday, the Planning Board will review a developer’s proposal to convert the old Registry of Deeds building into apartments. The building, located at 7 Russell St., dates back to 1904 and has sat vacant for eight years. Val Massard, senior planner for the town, said the plans call for creating 22 apartments: 20 one-bedroom units and a pair of two-bedroom ones. The developer, 7 Russell Street LLC, has proposed preserving the façade of the building, restoring the roof, and sprucing up the existing parking lot with new pavement and plantings. The Planning Board is scheduled to review the plans at 7:40 p.m. in the Mayflower Room at Plymouth Town Hall.