just a suggestion. on your next oil change, remove the bolt, go to the nearest auto supply. meron sila nyan. or kung wala na yung lumang bolt mo, just tell them na pang oil pan ng telstar
mas maganda pa din kasi sir kung may dala kang sample kung pupunta ka sa autosupply.... suggestion ko lang naman.... or, kung may malapit sa inyo na bolt and nuts na tindahan, dun mas malaki chance meron dun. hth