Lisa, 

I have a Bob Mize dulcimer that was made in 1990 and it has the same style of planetary tuners so I'd guess that yours are original to the instrument. 

If the cracks really bother you, wick a drop or two of slo-set Superglue into them...

Those tuners look like planetary ones-- the best.

Those look like good quality tuners, whether original or not.  It's true Bob like his wooden tuning pegs, but that doesn't mean he didn't fit these pegs to that instrument.  I would certainly go ahead and use them.  If they have trouble holding tune, there is a tiny screw in the end of each knob which can be tightened say 1/8 of a turn at a time with a small screwdriver to tighten things up.   

Lisa, enjoy your beautiful Mize!  

Lisa, you have a beautiful instrument. Bob Mine did excellent work. I do not think those cracks were there when he built that dulcimer. I think They are a function of age and humidity. I can't tell if they go all the way through the peg head or are just surface cracks. If the latter, let them go. If the former a little bit of thin super glue in the crack and some clamping will fix the cracks. Put new strings on it, tune it up, and play it. Enjoy your "new" dulcimer.

Ken

"The dulcimer sings a sweet song."

Lisa, this YouTube video shows a Mize dulcimer purchased in 1992 that has the same tuning pegs as yours.  I think they are original. 

About twice a year I treat my dulcimers to a rub down with Howard's Feed N Wax. The stuff is inexpensive and you can get it at any hardware or home improvement store.  Here is Bing Futch demonstrating how he treats his instruments with the stuff.

If this were my instrument, I would clean it up, add the Howard's, and then put on new strings. I bet it will sing!

Thank you for your response. I will search online for the product you recommended. The wood does not feel particularly dry to me. Depending on the light, the cracks are not as visible. That is why I did not see them at first. Maybe treating it will help. Would you try to go ahead and tune it as is? Also, what do you think of these pegs? Do you suppose they're original? The reason I ask is I read he mainly used wood pegs. Or maybe that was earlier than this 1984 instrument. 

Thank you. I did read that and decided to purchase based on that information. My concern arose once I noticed the cracking.  Could it have possibly been sold this way? I ask because the rest of the instrument is in such excellent condition. I have not attempted to tune it for fear of damaging it further. Also, I do not know how to tell if it is properly glued. 

I agree with John.  Those cracks do not look serious at all. They might have been caused by excessive aridity.  Does the wood feel dry to you?  Perhaps you could treat the whole instrument with some Howard Feed N Wax.  I bet you it will help rejuvenate the wood.

Lisa, the late Bob Mize was a legendary, quality builder of mountain dulcimers.  There is no question about that. The number 1922 is probably the serial number, or build number of that dulcimer.  Bob was very prolific.  The crack you indicate on the peghead should cause no problems if it's glued properly.  Mostly it's a cosmetic issue.  How fortunate of you to find this beauty!

I joined this site a few years ago after picking up an inexpensive dulcimer. I later realized it was most likely made in China. Following advice from this site, I changed the strings, and I could never get it to stay tuned. I spoke to someone fairly local to me and it was going to cost far more to make the instrument useable than what I paid so I eventually gave it up. 

Yesterday, I happened upon a 1984/1922 Bob Mize dulcimer. I have no idea what the 1922 means. I researched the maker’s name and felt like this might be an instrument I could learn to play. I attempted to look it over well, but once I paid for it and got to my vehicle I noticed a place in the wood in the peg area. I can’t tell if this occurred when the instrument was made or if it was broken and repaired. The instrument has no other marks on it and I don’t know that it has ever been used which makes me think it happened when it was built. My concern is if I have wasted money. Are these cracked looking places going to make this unplayable? I appreciate your feedback.