heya i have flight sim x demo and have fallen in love with it and am getting the delux edition tommorow

yayyy cant wait, any ways my question is , i had these 2 old pc usb controllers well one was a steering wheel , i ripped the guts out and solderd all new buttons and made a custom console wich enables me to hold down a momentary switch and my flaps close and i got this electronic key switch just to make starting the plane a bit more realistic haha, i have a total of 13 or so buttons and its not enough i want more so my question is is it possible to add more buttons?what i was gonna do is get another controller and rip it appart and by doing that i have a extra 14 buttons for $20 australian from harvey norman but if i can avoid doing that i will , i am open to all suggestions and or ideas as i love to experiment with electronics, oh yeah would like to see a few airbus planes for flight sim x made hint hint lol thanks