Can anyone tell me what I have here in terms of scarcity of this cover?

I was researching the Fairway cachetmaker history on another post and provide this excerpt from that research:
Quote:
The First Fairway Cachet was #610-2, issued with a 9/1/23 Washington DC postmark for the Harding Memorial Commemorative. This was the same day George Linn issued his historic "First True FDC Cachet" for the same stamp, in Marion Ohio. Fairway's #610-2 consists of a brown printed reply envelope addressed to Walter I. Plant of Washington D.C., with a printed general purpose eagle icon that was probably added later. (Monty et al., First Cachets Revealed, 2006, p. 5; Mellone, Planty Vol. I, 1994, p. 2).
Now I know this cover is postmarked Marion, Ohio, so it's not the first Linn; but since it does have the brown envelope, with the Walter I. Plant preprinted address and the brown eagle "cachet", could this be perhaps #2 of the first use of a Fairway cachet? In either case I imagine it would carry some sort of a premium over catalog value, simply being an early cacheted variety, whereas Scott lists only uncacheted values for that issue.
Any comments/help on this would be appreciated. Thanks.