Any ideas would be appreciated. Found 12 perfect slotted oil rings and 12 perfect compression rings in the attic. Have been told they are GM Factory Originals for '41-'48 Olds 6 cyl 238 cu in. They are in great condition. These are originals, guy who lived here worked for GM in Lansing. They have been in a hot dry and/or cold dry attic for 60 years? If you have interest in these please email foxinthehenhouse@hotmail.com