All About Pocket Knives

This is my first post so I'll start by explaining the contradiction between my screen name and the knife I need a part for. I mostly collect 1970s and newer slip joints but also like traditional, meaning two hand opening lock backs. Including the latter in my name would have made it too long. To keep the cost reasonable I choose relatively new knives and club knives over non-club knives.

I bought a 1987 ABCA stag Case 51050L SS through an internet auction. I like its stag. While this is not my only one it is the only one that came as a complete 2 knife set. Unfortunately the seller did not mention that its back lock does not function. There is no spring pressure on the lock's rocker piece or release lever. After opening the blade the end of the rocker has to be pushed down to engage the lock then slight pressure on the blade's spine will over ride the lock.

I mailed it to Case Repair. They say its "pollywog spring" is broken and they do not have replacements. As a substitute for free warrant repair they offered a small stag toothpick or a buffalo horn Cheetah. Neither one thrills me. I already have a variety of Queen made cheetah style knives and smooth buffalo horn is not my favorite. I asked if they'd scavenge a spring out of a user grade 61050L If I can find one and the answer was yes. I'm hopping to make that happen. Can any of you help with a source for the spring or by selling me a well used 1980s 61050L?

What do you mean by "user grade 61050 L"...not a pattern Case made in the 80's, as far as I know.

The two variations I frequently see examples of for sale on eBay are the 3,500 1987 stag ABCA knives that include mine and the 6,000 1983 NKCA brown bone knives. I'm not sure if there were any others besides stag Case Classics. I expect one of the 6,000 1983 NKCA knives with its blade worn down by sharpening would be the least expensive. If there were any others that were not club etched then in the same condition they'd be more expensive.

By the way, since posting I read the current thread on Coke bottles and learned a C prefix indicates the _1050 has a left or cap bolster rather than being bare head. All my modern large Cokes have cap bolsters. Only those with copperhead right bolsters have the C prefix so I assumed the C meant copperhead bolster. I'm sure there is a lot more to learn here.