I found an old photocopy of an article from a trade magazine that has a bunch of curves, including one for 12L14. I extracted some points from it:
H(Oe) B(Gauss)
1 500
2 3500
3 5800
4 7700
5 9300
6 10000
7 10600
10 12000
20 14000
30 15000
70 16300
Please keep in mind, these are only approximate values.