Ok ! Hey there! So I am mostly an N scale guy but I do have some HO trains I would love to eventually run on an HO layout. Cross your fingers for the future! I currently have two other Athearn blue box SP with Tsunami 2 decoders which are great. I wanted to add another to the fleet for a full consist of 3. A bigger loco of course for the front. I have my eye on one at the hobby store. Its got a very different paint scheme I haven't seen. All the walking areas are painted black as well as some of the nose. I'm assuming they did this for sunlight reflection but who knows. I'm not to historic on these. It just looks great but its $340. I'm saving but not now lol Here you can see the inside tab is not removable I don't think! My next great idea was this. I have had a old $40 (back in the day) Southern Pacific SD40T-2 That could possibly work. The motor runs fine and there is plenty of space. I ran into these guys (ready to roll retrofit decoder) from Athearn. They say they are pretty much drop in motor/decoders and then you hook the rest up. I've been looking and from the looks of them compared to my original equipment. The ends (driveshafts) coming out of the worm gears to flywheel connection look nothing the same. Even the push in tab that goes into the flywheel is not represented in the picture Here: https://www.ebay.com/itm/1333582862...wktpwy72T0QTFCHTMETFr3GeDUk=|tkp:BFBMyJK-nt5g I'm going to keep researching but thought It would be a cool thing to make a thread for. If you have any advice or ideas for connecting these let me know. I might even have to call Athearn to see if they have other parts of the drive shaft I can fit! Anyways Enjoy the evening!