Storm Door Lock, replacement outside knob

Hello, I need a new knob for my storm door lock as the spring is worn after many years and it does not return the inside handle to horizontal for proper engagement with the keeper. It was an Ideal Security from 1987 supplied by Hess Armaclad in Quincy, PA.. It was included in what I believe was their Hardware kit #10, features 1 & 3/4" hole centers, and the finish is antique brass. The 2" diameter round knob is fastened to a rectangular plate which is 2" W x 6" H. The inside handle is similar to what Ideal Security used on their old NA 1125 models featuring a lever-style handle with a vertical slide lock that features a round button which is about the diameter of a pencil. It is reversible for hinge L or hinge R installations, is black, and will function fine with a new outside knob. The outside knob has no key. There is a separate keyed deadbolt that still functions fine. I hope you can help by supplying me with a new replacement outside knob. Thanks & Happy New Year! John in Halifax, VA.

Thank You Dave, for your prompt reply. My lockset is indeed sort of like a fancy version of your 40-138. I'll consider the others also and decide. Thanks again! John