If the 45* PW is from your iron set, and the wedges are from a specialty model of wedges, you need to determine the distance gap + between the PW and the 50*.
+ See related thread on how shaft length influences distance between wedges: http://thesandtrap.com/t/59567/wedge-distance#post_728929
Next figure out the distance gap between the different wedges within the specialty model.
If the specialty wedges only have 1/4" length difference in shafts, this will reduce the yardage gap between the 50* and 56*.
If you can get fairly even distance gaps between the specialty wedges, it's not the end of the world if the PW and the GW fall 14 yards apart - as long as you know it.
With a little bending and shaft length tweaking, you might work your way toward 45, 49, 53 and 57. (again, see related post shown above)