I just put your numbers through Stu Millers Dynamic Spine Calculator using 0 center cut. I am not sure what a martin is cut at. The center cut of a bow has a great impact on dynamic spine.
with a BOP of 29.5, point of 125g, insert 12g, nock 11g, and 5" feathers the dynamic spine of the 150 is 63.4, If you stay with 12g insert and increase BOP to 30.5 the Dynamic spine will be 56.8
Recurve 50@28 and your draw at 27 center cut 0 and using FF string required Dynamic spine is 56.3
with +1/8 center cut 49.3
with -1/8 center cut 66.3
the CE 90's can be tuned to your bow too.
I have tuned several bows to various CE Heritage arrows using the calculator with great satisfaction.
If you have a spread sheet program on your computer and you want to try the calculator it may be found at.
http://www.heilakka.com/stumiller/ downloads for program and directions are at bottom of the web page.
I suggest reading the directions and doing a couple of run throughs.
Good luck
Les Heilakka