I picked up a Sharps model 1874 repro at a local gun show this morning. There's no sign of any maker's name anywhere on this gun. Any suggestions on where to look for hidden names of manufacturer on something like this?

Hi Ken,
Yes there is a serial number on the top tang, under the tang sight. I think I've solved the mystery too. I saw something sticking out at the edge of the buttplate, I removed the buttplate, and underneath I found a sales receipt for work that had been done to the Sharps. 
The list included a new barrel, bluing the barrel, cutting a rear sight notch, trigger work on the double set triggers, and fitting the forearm. According to the receipt, it's a Pedersoli, and the barrel is a 36" Green Mountain. I didn't know GM made a barrel over 34"? I pulled the wood, and can't find any info, so I'm guessing it was all on the original barrel.
The gun is chambered for .45-110, and the receipt for the barrel and other work came to more than I paid for the gun! Hope it shoots well!

No Ken, it's a 6 digit serial number. I know nothing about Pedersolis, and I'm just going from the receipt I found. There are only proof marks on the frame of this Sharps. That and the receipt tell me it's Italian for sure, and I guess the previous owner told the gunsmith it was a Pedersoli.