OK, took a look at the issue here. Shoes definitely seem to have some oil or grease contamination but there is no sign/evidence of where any oil or grease may have come from. Any thoughts?
Current - '74 TR5T : '93 R100R : '06 ST3s
Past - Variety of British, French, Italian, Czechoslovakian, and German bikes from the '70s, '80s and '90s