M1917 markings

This one saw Canadian service and has the red band painted on the forestock with 30'06 over printed in white. It has a few markings on the buttstock and barrel (see pics).

Can anyone decipher these?

I mean, apart from the C broad arrow ... and the E for Eddystone. :)

https://www.milsurps.com/images/impo.../M1917b2-1.jpg

https://www.milsurps.com/images/impo...0/M1917d-1.jpg

CHO - ?
Barrel was made September 1918. US ordnace mark.

Hart to make out in the pic. Maybe GHQ = General Headquarters rifle No.210? Just a guess.