You have of store credit. To use it, simply place your order and you will be able to choose store credit as the payment method when it comes time to pay for your order.
The Montblanc Meisterstuck series took shape in 1924 and is clearly their signature series. When someone says they have a Montblanc, its usually from this series. The 149 became the "power" pen in the 1970's-80's, cementing in the public's mind that Montblanc is the brand to own when you've arrived.