Roller Replacement
Thanks for reaching out to us. Unfortunately, I've never come across a tandem roller like what you show here. Its design is very unique. Based on the age, I think it's safe to say that this probably doesn't exist anymore.
One idea is to maybe use something like our 81-023, 81-279, or 81-004. These are educated guesses, though. I've never worked with your old roller before and cannot give you a good judgment as to what would work as a substitute. For now, review the dimensions for these three products to see if they would fit in your door.
You could also consider replacing the wheel by itself and just reusing the old housing, assuming it's in working condition. See our 81-266 and 81-272 wheel and axle kit.
We have dimensions for both the 81-023 and 81-004 on their store pages. I will share them below for your convenience; the 81-023 is 11/16" wide and the 81-004 is 3/4".
To be honest, I only recommended these because I saw the similar design in your photos and thought it was in some way related to the original door setup. If this was a newer part that you already purchased and didn't work, then I am far less optimistic that any of these will work.
Your best bet at this stage is probably to just try replacing the wheels. I honestly don't think you're going to find anything on the market today that can replace this. It's just too old.
