Managed to grab a couple of Linder knives (Indy's pocket knife from Raiders) from a store in Europe, and I thought it may be a good idea to update this thread with the info that's already been shared elsewhere: the Linder 312111 knife has been discontinued as of last year and it's becoming next to impossible to find. So if anybody wants one, you need to look for it now. In fact you should've been looking for it for the past couple of years. I had slept on this prop for ages because I considered it very low priority and I almost lost my chance to have one.
View attachment 1740557
To reiterate what VonMagnum said earlier in the thread, this is probably the closest candidate there is for Indy's Raiders knife and on top of that it's rather inexpensive. Thankfully there's still the Hubertus 12.300.HH.00 as an option, which appears to be a fantastic knife and looks virtually the same, but in addition of being much more expensive, it does feature a couple of notches on the metal top of the handle and gold finishes for several parts that are definitely not there in Indy's knife. Whatever they do to treat their antler handle appears to often give them a closer look to what Indy uses though, but knowing these kind of knives all have slightly different grips, I wouldn't consider that a key reference factor.
Anyways, the shop where I found these still had two more in stock, so if anyone is looking for one feel free to send me a DM and I'll point you in the right direction.