The George G. Bryan Post 284 in Belegrade is the only post of Missouri's 594 posts that there seems to be some confusion to the number of the post. Several sources including some very local ones call it post 254. But, that post in all the records I've seen belongs to a post in Forsyth.
There are no known records other than those that could be recreated from Missouri Department records. Death records are available as are the post rosters from 1895. I have access to both.
The only other references I've found include the below
In Pilot Knob Memorial Assoc book from 1906. Indicates post donated $5 to preserve the battlefield. Lists post number however as 254.
Very brief history of post in Goodspeed's "History of Washingtont Missouri" page 522. History states town has two general stores, one millinery store, post office and a blacksmith shop. Meetings apparently in one of those buildings.