need a little help please

got these 2 mounts in some stuff i bought. need help identifying please. the one that has the biscuit on it appears to be like my drivers side 340 mount EXCEPT it needs the top corner added as seen on several posts on this site. the black one with no mount looks right BUT holes for biscuit need to be on other side. what do the experts say? tia. rick w. 20220320_164543.jpg 20220320_164532.jpg