Are those examples of the famous 1959 rotary valve Pope? They look like it to me. If so I suggest you keep them - I haven't seen one in 50 years now.

You can see some pictures of the engine here, if you go right down to the bottom of the page:
http://www.vintagekart.4t.com/photo_46.html

They were discussed in passing in a thread, here:
https://www.outdoorking-forum.com.au/forum/ubbthreads.php?ubb=showflat&Number=35018#Post35018