I have a NIB (never been fired) Spike's 37mm launcher, it is the 12 inch model with the slots at the end. I emailed Spike's about this and they stated it was a special run they made, and is no longer listed it is very similar to THIS
. As you can see, they do not have any in stock until March.
$225 shipped, payment via USPS MO only.
I also have a USGI rail mounted sight system much like the one that is on the dedicated forearm, but mounts to your rail system. $50.00 with the 37mm.
I will get pic's up as soon as I can.
ETA: Just for reference this is the exact launcher: