Hi there!
I just saw your project and was interested in working on it.
I am Pranav, an electronics developer, schematic builder and PCB design expert.
I can make the Circuit and lay out a PCB together with the microcontroller, SD card slot, pushbuttons, etc. for you. I will require only 12 hours for that.
I cannot however make an enclosure for you, as that is something I haven't done before.
However I can guarantee that the entire board wouldn't be much bigger than the SD card socket, + CR2032 battery. I can make it really small, and save components. You really don't need two buttons, for example. Also you could use one RGB led instead of two leds. Blue when no card, Red for locked card, Green for unlocked card. Same pushbutton powers on the device, and it turns off automatically after 30 seconds of no activity.
Do get in touch with me for more details. I can begin work right now.
Also, regarding payments.
The bid amount is for component selection, schematic building and PCB layout design, and programming only. It does not include PCB fabrication or any components. For prototype, you will have to pay for the PCB fabrication and components, + shipping to USA.
Also I would require an initial payment of $15 before starting the work as security since you do not have any reviews yet. Sorry for that trouble, buttrust me, I've been looted before.
Looking forward to working with you..
With warm regards,
Pranav