Dad's Army 3x13

The search begins for a butterfly spring for a Lewis gun that Frazer has lost whilst cleaning it. The trail leads them through Frazer's workshop to a Funeral Director, to Mr. Bluett's dining room table, to a graveyard. The platoon stops at nothing, committing various crimes including house breaking and grave robbing to get the spring back. But will they find it in time to save Frazer from a court martial?