It's unlikely that there ever was one.
Luckily, you don't need one. A generic bicycle maintenance book will tell you all you need to know and then some.
If there's anything missing, most component makers, (Shimano, Rockshox, SRAM etc) have good tech support documentation on their websites.
Dealer, Salvage Yard, E-Bay, and many on-line sources. Search Google with the term, "Automobile Owners Manual" Actually, I have found that Lexus will send an owners manual if you just write them and ask them. Simply say you are a Lexus owner and have misplaced your original manual. Try it.
The original manufacture of the Iver Johnson Model 55 Target pistol maybe able to provide an owners manual. The manual will have instructions on what is need to maintain the product.
I have the original owners manual and the jig saw along with an older saw. I could scan it if you want and email it. Bob
For the information go to http://www.stevespages.com/page7b.htm To get an original manual, try eBay
Send me your email & I'll send you a scan of the manual. If you want to purchase an original manual you can try eBay or gunbroker.com but most of those are just copies of an original.
Ebay is a good place to start for general used items such as this.
Do a google search for JC Higgins Model 29 and you will find a downloadable PDF file for the original owners manual. That is where I got mine and yes, it is the original owners manual. The gun was made by High Standard for Sears Roebuck starting in about 1955 or so and you can find some parts for it at Gun-Parts.com.
The probable place to download the manual for your car is the site of the manufacturer, General Motors Co. Get help there.
You can get the same diagrams and parts list that are in the original owners manual on the sears, partsdirect web site by typing in the model number. However many of the parts are listed as no longer available.
See below for the Owners manual.
Crosman has the original Owners manual online. The loading port in on top of the barrel. See the link below for the manual.
if it is not in your owners manual open the jack storage look forward and you will see a box on its edge with wires coming out of it your original number is on a sticker on that box if it is not in your owners manual open the jack storage look forward and you will see a box on its edge with wires coming out of it your original number is on a sticker on that box