They made a Baby Ben version of the same clock. These Westclox were apparently the "standard" of the day. A quick search showed quite a few up for sale ranging from $30 (dilapidated) to $350 (good condition). But seems like I could pick up a couple old ones cheap to use for parts. Also found a YouTube vid from 2013 (2:33 in is the version I have) made by a guy that collects just these. He went into a lot of geeky detail about the differences and when made, but from that info was able to peg that the version I have was made between 1923 and 1925. He also said the internal parts are all date stamped.I do recall my great grandfather having a similar one, but smaller perhaps than yours.
They really made shit to last forever in those days, didn't they? Also have my grandfather's old railroad pocket watch. He worked on the railroad his whole life. The watch is well worn, but you can still see the outline of a steam engine on the back of the case.
None of it is really worth anything much but just having those is huge sentimental value to me and connection to my family generations.