I think they should go with something like this. Maintain the original integrity and essence of the overall design, honour the mid-century architectural while adding density.
They could easily add some height to this concept and perhaps closely achieve the desired # of units.
The tower design could be altered to achieve a look somewhat like Telus Gardens. Not only would this compliment and preserve the overall design but the less bulky massing would preserve light.
source :
http://www.vancouverheritagecommunity.com