I know it's a bit of a turd-polishing exercise but I like the model so I have ftted a Black Beetle to my Hornby Class 110. As I was bending a piece of metal to shape to fit the motor support I spotted that a spare piece of spur shelf slotted square angle was exactly the right size. With only minor filing the Black Beetle fits inside the channel, which I cut to the right length to fit the bogie frame fomr which I'd cut and filed only a fairly limited amount of plastic. Add a hole in the middle and the result is a frame that the motor drops neatly out of for servicing. Tidy! This is on my list of things to get pictures of.
Once again the "come in handy" box comes up trumps!
-- Guy