So now I got parts in hand and I can not worry bout getting screwed. These were up for sale on another site I troll for parts on a regular basis and I just couldn't turn the price down. I think I got the Wholly Grail of Cogs. For sale for multiple days and no one snagged it I saw it and it was sold same night. Yes that is a 10 1/4" lower quick change Cog. Multiple people told me that nobody made one. I now have one and hopefully can put it to good use next year after I go built. I can have an engine around that cog right there. Life is gonna be fun.