I have been lucky enough to find a few older Remingtons, including a barlow (pen blade is just a pin pretty much), two blade curved jack (most of both blades left) and two blade jack (gave it to a knife maker). All three were older, I am still uncertain as to who made them.
Remington made knives up until about 1939, then I believe they sold the entire knife line to PAL (correct me if I'm wrong please). There are lots of fakes out there, just because it has the Remington shield, the circular and model number stampings, doesn't mean it's a true Remington. The two blade jack I gave away was most likely made by PAL, because of the straight line Remington logo. My Remingtons were used and not really collectors items, but still have great walk and talk.
In the 1980's, Camillus made knives for Remington using bone delrin scales and 440A steel. Really nice looking, they can be quite expensive. I have a scout knife from the 90's or late 80's, and I have a 1984 R1303. Both have been carried, but I've been keeping the R1303 on the shelf as of late.
After Camillus went out of business, I heard that Bear and Sons picked up the contract. I think that was around 2004? Most USA made Remington knives should have a date stamp on them. Lots of them are made in China. I have heard that the Bear and Sons models are not of the same quality as Camillus, to put it lightly. Also, there is a noticeable difference between the knives made in the 80's and the 90's, not just scale materials.
Personally, I like old and Camillus models, they are the yardstick of slipjoints. Tony Bose's catalog is comprised of a lot of Remington designs. A lot of manufacturers today are using old Remington designs, like the 73 Trapper for instance. I haven't had any problems carrying either my old ones or the Camillus made models.
I found mine at junk/antique malls, and they were used. I've seen prices at local knife shows, and they are too rich for my blood, but that's just me. It might be a steal for someone else.
I think there are a few books out there about older Remington slipjoints.