Don't know if it's just these two or a general rule but yours has a Johnson 111, which is more in keeping with the time it was produced, whereas the Bumslot has a Mabuchi S can. Wheels are different, but apart from that and the velcro fitted to the chassis of mine to hold it in the box, they look pretty much the same. Even the A120 moulded in to the underneath of the interior is the same.
So, is that another make to add to the growing list?