Bachmann manufactures an HO EOT device shown in Fig 1 that works quite well.
Fig 1 Bachmann EOT Device
There is one problem with it however. Notice in figure 1 that the mounting hole is larger than a normal 2-56 mounting screw. Yes, that's right, it takes a somewhat special screw to mount it properly. On some of the forums there has been discussion of using washers along with 2-56 screws but this can lead to coupler height issues.
So, after some research the author found the correct panhead screw to use to mount this EOT. See Fig 2.
Bachmann parts has it and it is hard to find but it is located here. They do not come in packs but are sold individually. You can order up to 20 of them. Bachmann takes all major credit cards along with PayPal.
No more washers or misadjusted couplers.
Fig 2 Pan Head Screw
No more washers or misadjusted couplers.
If you have an idea for a blog post here, let me know. If I can comment on it, I will or I'll see if someone else can and post it.