The knife, a Press Button Knife company sterling silver handled double button switchblade made around (according to the inscription) 1916. It's about 3 3/8" long as was designed by George Schrade. PBKCo. Was his first venture into automatic knives I believe.
The biggest problem was the broken backspacer. This was probably caused by someone exterting a lot of force trying to cut something they shouldn't have. Many people mislabel this part as the backspring. It has no spring action at all. It's sole purpose is to stop the blade in the open position and keep the liners spaced evenly apart.
The pen blade had no button tension at all. Upon disassembly it was discovered that the combination sear/button spring had come unpinned
The master blade's button operated fine but the blade would no lock open or closed. I determined before disassembly the problem could be due to either 1. plugged sear holes or 2. a sheared sear. Upond disassembly I noted it was the latter, a sheared sear pin.
Other problems included weak firing blades that would barely open, smashed and dented handles,and the master blade peeked.
After a few hours at the bench it was operating just like new.
I do not recommend working on vintage schrade designed automatics. They are extremely difficult to work on (especially PBKCo.) and are not for the faint of heart, beginner or amateur. MANY more things will go wrong then can go right, and there is no sense in tearing it up any more trying to fix it if you don't understand their mechanics. Schrade designed automatics are one of my specialties and I have learned what I know solely through trial and error on my own knives until I developed a good understanding of what made them tick. I have lots of practice at working on them. Probably the easiest and most simple design to work on is the pullball knife, they are the exception. All of George's other designed are in a sense built from the outside in. The knife must be assembled before the handles can be installed and if you need to get at the blade or backspacer you'll be disassembling the ENTIRE knife down to the last pin. There are no shortcuts. On most 5" single blade models there are in excess of 18 pins and rivets that hold the knife together and most were pressed in and very difficult to remove without damaging the knife. I'm not trying to blow my own trumpet. It's just that the only thing I hate about my job is having to fix the mistakes of the uninformed, that could have been prevented. You've been warned!
