HHKB SmartCard reader modification?

[HolidaySHRIMP]

Originally posted on Reddit (http://www.reddit.com/r/MechanicalKeyboards/comments/166kn7/enough_room_inside_hhkb_to_mod_a_smart_card/) and decided I'd post here also.  I use my HHKB for work exclusively and require the use of a smart card all the time to VPN in.  I think it could be done and the keyboard has the USB hub so it can have connectivity also.

I'm thinking the red line for the slot can be used to guide the smart card in for the top half and some sort of internal guides need to be created for the other half of the sides and a stopper.  This specific smart card reader has torq screws to access the PCB and the guts that we want.  I'm sure there are readers with even a smaller foot print.  Can any experts chime in on this?  I don't want to go cutting into a $300 keyboard just yet.  I do own a dremel with a cutting wheel that can be used to cut the slot.  I've been looking around for tear down of the HHKB but can't find any good pictures that have measurements and the angles that I am looking for.  Currently I am at work and can't take apart my keyboard right now because I need it for work 

Proposed slot to be cut: