B65-573 INCLINOMETER. Gibson Plumb & Level Mfg. Co. Uncommon inclinometer patented by William Gibson in 1907 and manufactured in LaHoma, OK. 24" stock, 1-3/4" thick which is typical. The ring holding the rear cover plate for the mechanism is missing and the glass cover is taped in place, but other than that it's in near mint condition. Turn that side to the wall and you've got what appears to be a mint condition Gibson at a bargain price. From the collection of David Jeffers. Good 60-120