Mad keen about making toys, here's a connective part (8)
I believe the answer is:
keystone
'a connective part' is the definition.
The definition and answer can be both man-made objects as well as being singular nouns.
Perhaps you can see an association between them that I don't see?
'mad keen about making toys' is the wordplay.
'mad' indicates anagramming the letters.
'about' indicates putting letters inside.
'making' is an anagram indicator.
'keen' with letters rearranged gives 'kene'.
'toys' is an anagram of 'ysto'.
'kene' enclosing 'ysto' is 'KEYSTONE'.
'here's' acts as a link.
Can you help me to learn more?
(Other definitions for keystone that I've seen before include "Piece at the top of a masonry arch" , "Central part of a system" , "Important piece at apex of arch" , "Something on which all else depends" , "Central part of arch" .)