I looked at micro-trains, I model N scale by the way, website already, but is there any way to put an operating front coupler on a Bachman 4-8-2 or a Rivorssi 0-8-0?
Can’t say for sure about N scale, but you can put a Kadee coupler on the front end of just about any HO scale steam locomotive, although in many cases, you may have to do away with the draft gear box. This means no self-centering action, but the real ones didn’t have that feature either. [swg]
If the loco has a dummy coupler held in place with a screw or pin, pick a suitable Kadee coupler and alter its shank to resemble that of the dummy, then drill it to accept the pin or screw from the dummy coupler. Coupler swing may be limited, and if you need more, either enlarge the width of the opening in the pilot or go to a coupler with a longer shank.
For the 0-8-0, with no lead truck to get in the way, you should be able to install a coupler and its draft gear box, although you’ll likely need to enlarge the width of the opening in the pilot. Attach it with a screw, and you’ll have a fully-functioning coupler.
Wayne