[unsen]

i wonder if you tried already: make yourself a rope-bra. tie it really tight above and below your breast and then wrap some slopes connecting the upper with the lower ropes tight together on the sides and in the middle.
them you have tight slopes around your breast you can try to pull them through as much as you can, causing your breast stand your nicely.

maybe a task for the library? leave it on and stroke and pinch your nipples under your shirt from time to time.. choose a more daring one and try to sit and walk straight most of the times when people around. i think this is not against your bra-restriction and though you may fool people into thinking you have bigger tits. give them little chance to see somewhat at least.