rare 1947 KEUFFEL & ESSER SLIDE RULE IN SHEATH~4081-3 LOG LOG DUPLEX DECITRIG For Sale

I BELIEVE THESE ARE VERY COLLECTABLE, NEVER HAD ONE BEFORE AND I SEARCHED THE INTERNET AND THIS RULE NUMBER DATES IT TO 1947. A KEUFFEL & ESSER CO. N.Y., LOG LOG DUPLEX DECITRIG #4081-3. THIS IS THE NUMBER ON THE RULE AND THE WEBSITE SHOWS IT AND DATES IT ON 1947. COMES IS ORIGINAL SHEATH THAT HAS A FANCYSTAMPED NAME ON IT OF \"WILLIAM McGAGHIE\", AND THIS NAME IS ALSO ENGRAVED ON THE TOP LEFT OF RULER, MUST HAVE BEEN A IMPORTANT PERSON. EVERYTHING IS IN GREAT WORKING ORDER AND APPEARS TO BE IN GREAT SHAPE,,, THE ONLY FLAW I SEE IS THE PIECE OF GLASS THAT SLIDES HAS ENDS ON IT TO HOLD AND ONE SIDE HAS BROKE AND THE OTHER IS CRACKED, BUT YOU CAN STILL SLIDE IT GREAT HOLDING THE METAL FRAME AND IT DOES HAVE LITTLE SCREWS IN IT WERE YOU CAN REPLACE IT IF WANTED, THE REST IS VERY NICE. HAS MARKINGS AND WORDS ON CASE AND RULER,,,,,,,, PLEASE SEE ALL PICTURES AND ENLARGE THEM FOR BEST DESCRIPTION AS I KNOW LITTLE ABOUT THESE. A GREAT ADDITION TO ANY COLLECTION, THANK YOU VERY MUCH