For what it's worth, I don't believe this clock originally had a gong on top. Bell, yes. Gong, no. The groaner movement was made by Chauncey Boardman of Bristol, CT, but could have been cased by any number of clock makers.
It's an absolute hodgepodge of parts and pieces. The weights don't even match. I suspect someone was having some fun and using some ingenuity to do it.
However, one might consider your clock as being what is called a "make do".
Before we adopted a mentality of disposability, things weren't just tossed out when they broke. They were reused. I suppose a form of the "adaptive reuse" that has now become so popular these days. One big difference is that with the latter, often an antique is destroyed to turn it into say a hipster w(h)ine bar as is done on TV programs like "Flea Market Flip". Granted, it is sometimes a fragment or something damaged that was destined for the trash heap and now made useable again.
With a make do, usually what was already broken was used to make something useful. The broken off base of an oil lamp might be used as the base for a pin cushion, a tin handle added to a pitcher that lost the original one, etc.
Looking at your clock reminded me of something. A very early form of American wooden works shelf clock is called by collectors a "box clock".
On the first of those, there was no dial per se. The numbers were painted on the glass. On your clock a similar situation but using stick on #'s. I'm sure the parallel wasn't intentional.
Yes, I thought that perhaps this was on of those "custom" clocks. Actually the numbers look like they're stuck to the glass, but they are in reality on a cut clear plastic piece inside used as the face. About the same idea I guess. Clock will gong and run for a short bit but then stops. Could be an adjustment issue.