vt, You seem bound and determined to go ahead cleaning it up, but just a word of caution, from my personal experience. Many years back, about 1980, I bought my first Nice Kentucky. It had some carving on it, looked good, but was a bit grimy so I thought I'd just give it a light cleaning.
A friend recommended something named Murphy's wood oil soap, or something like that. I followed the directions and put a bit on the wood, rubbed it gently around with a soft rag, and yep, I could see the dirt coming off. But when I took a clean rag and wiped the stock off my eyes about popped out of my head, because all the old original shellac finish was gone too!
And try as I might, I was never able to reproduce that finish.....
End of sermon,
John