Thank you for the info!

I talked to Barclays security dept again 2 hours ago and got a lady manager who happened to have the ability to "activate" the mastercard securecode. She told me to wait an hour or so before trying again but she said the code was activated (?)

Did not try to mess around the Mastercard Securecode site again but went directly to retrieve held reservation at TK site, made a payment with the A+ card - it had a pop up window but did not require me to do anything, then a second pop up window which was completely DARK, I fully expected a failure -
BUT it went thru!

Saw this information on the top of the page
Credit Card: ************xxxx Authorisation Code: xxxxxx

The total amount has been charged to the indicated credit card during the payment. Your ticket has been issued as an electronic ticket. You will not receive a paper ticket.
.................................................. .................................................. ..............
Email confirmation took a few minutes to arrive and the attached zip files DO NOT contain e-tickets but the Rules of the tickets!

However I was able to retrieve the reservation on TK site, and then the details show the e-ticket number next to each passenger, and I was able to print a PDF file of each ticket. Whew!

Tickets also show up on Saudia site with coupon status - Open to Use. I am so thankful that Saudia site is using IATA data base for Manage My Booking so one can verify any e-ticket from any airline on its site. A Godsend.

Still have another ticket to purchase, now knowing AMEX Plat also works this is much appreciated info.