These are pretty rare and I only received one unit in stock. This one's the "M" version requiring the removal of the rifle's delta ring.
Asking price is $379 plus $8 for shipping and insurance. As a package deal, I'll throw in a #40 flip up rear sight or the #22M68 Aimpoint mount for an additional $87.
For payment, I accept Money Orders, Personal Checks (held for clearing) or PayPal from verified accounts with confirmed address.
I also have the #45, #46 and #51 SIRs in stock and ready to ship. I'll do my best to match prices, just shoot me an e-mail!
Please let me know if you have any questions!