I don't escrow WebMoney.  I only escrow bitcoins.

Also, regarding the recommendation to contact John K., note that he has not been signed on to bitcointalk since May 18, and he hasn't posted anything in the forum since April 18.

You can try contacting Tomatocage or LouReed. I'm not certain if they are willing or able to convert WebMoney into bitcoins for you.

Your best option will probably be to get a WebMoney account for yourself, and then exchange WebMoney for bitcoins, litecoins or dogecoins once you have the WebMoney.  The next best option would be to convince your buyer to exchange his WebMoney for bitcoins, litecoins, or dogecoins and to then send you bitcoins for payment.