Ok Peter, pulled mine apart for you.

As u have pictured the wooden frame, it sits the same way u have it pictured in the picture except you need to roll it forwards so the frame is sitting flat instead of on its back.
The square side sits to the left (outer side of the pinballs left cabinet side).It slides over the cannister so to speak, BUT you have to take the silver ramp off first, then you have to take the lid of the cannister off first. There is a small screw holding the lid of the cannister on, the small screw is located on the left side of the silver cannisters lid. then you can lift up the cylinder guts.
Note, You will see various stuff inside it and a few wires going under the playfield too.

It is a little complex. I took mine apart real slow, but by answering your post, u did me a favour cause i found alot of loose screws n stuff ! Mine works fine, but i didnt like the loose stuff. Something was to fail sooner or later.
I am going to do a search for a Manual, I will be happy to post you a copy of it. I will have a look on the pinball database etc, but i always buy hard copy originals for all my machines when i can get purchase/them.

It does look good with the wooden piece on, but it is a pain to take stuff off to get to it.Best to wait for a manual, cause if u have loose stuff like me, i dont want u to stuff up the multiball lock just for the look of the wood piece. the exploded views of the manual should work a treat. i will keep u posted about the manual etc.
kind regards,  Brett