The list on the website you mentioned is not a complete list of the flags in their collection. I wrote to them several years ago, and was told that the list only represents the flags the flags that they have done conservation work on so far. When I wrote asking about the 137th NY they told me one was about to be conserved (now viewable on their site), but they had something like 3-5 others for the unit and they gave me info on them. I'm sure they will have more information like what you are looking for. Unfortunately, their site says that due to budget reasons they can't answer by email anymore, so you'll have to send a snail mail letter asking them, and might have to pay a research fee. If you have some time you might want to look into this.

Josh Bucchioni