Eric,
When you check with the Guard, ask them if they know where the morning reports for that Regiment and that particular company are archived. If you can get copies of them and they will probably be in microfilm which will require you taking them to your local library to use a microfilm reader. Most everything that happens in that company hinges on the morning reports, pay,Etc..
Once again, in Illinois any that exist are in the possesion of the archives dept and probably the same there. Some are at the Army War college in Carlise Pa, but I would guess that they are only copies of that which is local.
FC