Federal Early War Issue Haversack

[wade03]

Hello List,
I was wondering If anyone knows where I could find a detailed research of the basic federal early war issue haversack(with the copper rivits or sewn strap) I'm looking for measurements, small details, and even pictures would be nice. The resaon i ask is because I currentaly have Jarnagins "early war haversack" and was wondering how far it is off from the originals, and if its worth modifying it.
thank you for all of your help in advance,

[Western Blue Belly]

The CRRC II is quite possibly the most useful book to answer this and other quick questions like this.

[wade03]

Thank You Ken!
I'm fairly new to this. I'll have to buy that book, looks very helpful.