This model is a nice representation of a rebuilt USRA single sheathed boxcar. Veteran modelers will notice that the InterMountain model is the same as the Tichy kit, so these instructions will apply to both. This conversion is super-simple so it's a good one to start with.
Once the old coupler is removed, use non-magnetic tweezers to place the friction spring for the Prototype Couplers coupler. There are tweezers and then there are "non-magnetic" tweezers. Non-magnetic means that the tweezers won't become magnetic if they are exposed to a magnetic field (like the one surrounding the earth). You want the "non-magnetic" variety. Otherwise, the spring will stick to the tweezers and you'll be trying to shake it loose. The non-magnetic variety will almost always have something to that effect printed on them. Don't assume that stainless steel tweezers are non-magnetic because stainless steel is non-magnetic. Not all stainless steel is non-magnetic.
I found some nice non-magnetic tweezers at a train show. I have also seen similar selections at flea markets. It's good to see how they feel in your hand before purchasing. You don't want tweezers that require significant force to operate. Too much force will cause the springs to fly away (you'll put your eye out!). If you don't typically attend train shows or flea markets, you can buy a set of good tweezers from McMaster-Carr PN 5669A12. These will set you back about 10 bucks by the time you pay shipping charges.








