Got the last couple examples of this lens, this time with some imperfections.
Serial number: 8054166 includes the dedicated extension tube, has an engraving on the focus ring and extension tube: ET #10. No other flaws, looks near mint beyond the engraving. $65
Serial number: 8047581 includes the dedicated extension tube, has an engraving on the barrel and the extension tube: ET #1, and has a small coating defect in the front element. No other flaws. Flaws shown in last two images, pretty hard to get it to show up aside from the backlit through the lens shot. $50
Prices are plus shipping, or will trade for film: 35/120.
Serial number: 8054166 includes the dedicated extension tube, has an engraving on the focus ring and extension tube: ET #10. No other flaws, looks near mint beyond the engraving. $65
Serial number: 8047581 includes the dedicated extension tube, has an engraving on the barrel and the extension tube: ET #1, and has a small coating defect in the front element. No other flaws. Flaws shown in last two images, pretty hard to get it to show up aside from the backlit through the lens shot. $50
Prices are plus shipping, or will trade for film: 35/120.