Allow me to introduce myself ..............

[Gryphon]

looked closer at the underside of the tank. Left side, very close to the rear (farther back than the petcock) is a threaded plug. Could that mean it is an IS tank?

That looks pretty close to where the threaded pickup is to my belly tank.  It also looks like there is a hex base on the fitting the plug is threaded into.  I would guess that the tank was originally attached to an R&M belly tank.  I love my extra range. 

[old2soon]

Looks like yer gittin yer feet wet on the Phatt Ghurl pretty good.  These things-Valkyries-ARE addictive.  Just so you know!  Carl' suggestion-Willow-on running the fuel down the filling up would be the way to determine which tank is on your gal. Liking the blue but I have the green and silver I/S. You WILL get tired long before the Valkyrie does.  Welcome to our sand box-Don't feed the inmates UNLESS it's B B Q and cold adult beverages!  Again-WELCOME from the Sho Me and RIDE SAFE.

[srteach]

found out that the fuel shutoff had a hole in the diaphragm. Good thing the repair kit is on order.

[lonewolf/va]

welcome