With the recent ICON discussion asking the question, "What is your Holy Grail?", mine would still be finding another unmarked Thomas M-3158 early gray multipart like mine. Since these were used in my area in the 1920's, I have been searching for the cemented in pins in a recently disturbed area with the underbrush cut on part of the original right of way with my metal detector set to 'rusty metal'. Hard to do since it's a bit dissapointing to find a hit and then dig up a tin can or an auto part. I once found part of a ship's anchor chain! But I will be patient until my Holy Grail appears. Nowdays, I just chalk it up to "retirement fun" !