Melvin R.Tressler;80;of 1004 Second St.;Monessen;died Saturday;March 23;1996;in Mon Valley Hospital;Carroll Township.  Born Dec.20;1915;in Fort Hill;he was a son of the late Rynaldo and Myrtle Snyder Tressler.  Prior to his retirement;Mr.Tressler had been employed by American Chain and Cable Co. of Monessen and Dravo Inc.of Charleroi.  Survivors include his wife;Alice O’Toole Tressler; a son and daughter-in-law;Martin R.and Kathy Tressler of Rochester;N.Y.;three daughters;Mrs.Terry (Janet) Yeager of Lock Four;Mrs.Dennis (Patricia) Urchick of Portage;Ind.;and Mrs.Robert (Bonnie) Besong of Baden;nine grandchildren;three great-grandchildren;nieces and nephews.  Friends will be received Monday from 2 to 4 and 7 to 9 p.m.in the Rhome Funeral Home Inc.;1209 Grand Blvd.;Monessen;where services will be held Tuesday at 10:30 a.m.  Burial will be in Belle Vernon Cemetery.  The Rhome Funeral Home Inc.is in charge of arrangements.