Looking to trade my lightly used 2" 2x Big Barlow for your 2" 4x Powermate. I'd also take the T-ring adapter if you've got it. Mine has original box, caps and 1.25" adapter and so should yours. I can make up the balance with a cash payment from paypal (so no fee).
Sorry, not looking to sell my Big Barlow until I find the Powermate, but will buy your Powermate outright.
And still looking for a 12mm Nagler Type 4! Name your price!