[Mark L]

Prior to posting my message here, I did search the internet for several hours. That's how I was able to identify them as made by Houdaille, but none of the information I found definitively identified them as a particular assembly number or year of manufacture. My impression from the Applehydraulics website is it looks like they use some of the same photographs for different assembly numbers. I independently found the bulletin that glennpm attached to post #6, which has great photographs, but none of the numbers on those pages match the numbers stamped on mine. It does help identify what mine are not, and narrows them down to fewer possible assembly numbers.