Some sort of file holder or clamp?

[robinpeck]

What is this tool? It is some sort of file holder or clamp. It is holding a file in the photo. The holder itself is approx. 4 in. long and the file and holder together in the photo is approx. 10 in. long. I'd appreciate it if someone could identify it and tell me about it. Thanks, Rob

[jimwrench]

 You have a saw jointer (used to even the height of saw teeth). This one was patentd by Edwin Pike (patent 507386). Probably manufactured by Pike Mfg. Co.

[robinpeck]

Yes, thanks for confirming....I found this out myself just now...

PIKE PERFECT SAW JOINTER, Levels the teeth on rip and crosscut handsaws before sharpening. Pat d Oct. 24, 1893 in the earlier cast-iron frame. It's spring-loaded to hold tightly to the saw to "joint the teeth absolutely true". Very respected manufacturer in New Hampshire.