This is a wonderful old Japanese-made regulator wall clock, nicely embellished with relief carving, dating to about 1890 - 1910.
A branch of the better known, Seiko company, Seikosha of Tokyo were in operation from 1892 to 1923. This particular model is an imitation of the style of German carved "Black Forest" regulator wall clock that were popular at the time, complete with those lathe turned spindles that help to pinpoint the date.
At about 50 inches long, this was the largest model that Seikosha made.
Looking at comparables (and there are not many, this is a hard-to-find clock) this one very similar to your friend's (but with a Roman numeral chapter ring and different carved molding), sold on line for $300 but was not in working order and had some repair issues with the case too.
I would give your friend's an auction or on line (eBay etc) value in the range of $400 - $600.
It would therefore have a full retail value of $1200 (if you saw it for sale in an antique store, say) which is also the replacement value for insurance purposes.
I do hope this helps!
Please let me know if I can be of further assistance with this, I would be glad to.