Sekisui. This would be old Con-Cor. Many years ago. It can be done. Critical will be the height of the converted coupler. Seems to me we used to fit one of the Minitrix FM conversions into such coupler pockets. (It has been long, long years since my last time.) Otherwise you will be grinding that whole box off. Do you have a Dremel?
I do have a Dremel. After I grind the boxes off, would I replace the trucks with MTL trucks with couplers?
Not trucks with couplers, there’s a coupler that screws thru the floor. I bought an atlas converted this way to cut up and use for my concor bay conversion. You will need to trim the screw back, and personally I’m going to put one teeny tiny dab of glue on the pocket just to be sure it stays. Those screws will vibrate loose in time.
If that coupler pocket pops off you could always use one of these possibly. Hard to tell without seeing a photo with the piece removed. https://www.micro-trains.com/index....couplers/universal-coupler-1129-2-pr-00130013 My Atlas front runners and a wide vision cabooses still have these installed to this day.
You do not need to replace the trucks, but can if you wish. I am trying to recall- is the pin holding trucks on a solid shaft? Or a split pin that pops in? If the latter, the hole is too large for an MT pin and needs an adaptor plug to be pressed in first. These plugs used to commonly come with MT trucks. I hope they still do...?
If you are not doing a lot of coupling and uncoupling for operations, you could also remove the box lid and install a Fox Valley (formerly Red Caboose / Unimate) dummy coupler. I use these on most of my cabooses and they couple well with most of the common knuckle couplers (Micro-trains, Accumate, etc.).
This being an older Sekisui, there is no box lid. The entire chassis is a solid casting. It may be open on the top side, where a conversion may fit down into the factory box. Otherwise, it must be cut and ground off.
