Only the second one picks up Radio stations dunnit dad?
There you go one 8" and two 6" some people fix the centre piece top and bottom
In the standard 6" mantle clock I use inserts about 70mm but not the type that are held in by a rubber band I prefer the inserts with three spring steel retainers on the 8" clocks I use the 100mm inserts so as you can see the insert is about half the size of the bandstand here are another few designs of different clocks the last two have watch inserts
I made this clock some time ago.I made my own drawings up. About 240mm high, the base is about 120mm diameter and it is a 50mm clock insert. Hope this helps.