I'll move it right after this post.
You have identified your trucks as Jammin X1 CRTs, very nice trucks, still raceworthy despite being somewhat older models these days. Spares are still easy-ish to find, but they are starting to dwindle a bit. I wouldn't expect them to disappear completely for a long time yet. The OFNA .28 engine is a decent budget engine, nothing special. The OS V-Spec is a high quality racing engine.
Obviously all my information about electric is irrelevant, when you said speed control (which is a very specific electric term) I assumed the cars were electric. Although...that particular car does very well when converted to electric.
