This is probably splitting hairs, but I do not agree that 055M15 is equivalent to the old EN3 grade. The new 070M20 is obviously identical to EN3A, but I still think this is a better equivalent based on the C & Mn content:
EN3 0.25 max C 1.0 max Mn
EN3A 0.16-0.24 C 0.50-0.90 Mn
070M20 0.16-0.24 C 0.50-0.90 Mn
055M15 0.20 max C 0.80 max Mn
Anyway, it sounds like you found what you needed. Good luck.