lettering of BLI H2a Hoppers

[nw-modeling-list at nwhs.org]

Hello,

I am totally new in both: this email-group and also Norfolk and Western RR.

Can anybody help me, to decide, which models of the Broadway Limited H2a-Hoppers I have to take?

There are, as you all know?, two types: with 17" and also 24" lettering, but I can't find any information at the moment, which are the right ones for my future projects.  I'll prefer the time between, let´s say 1940 up to the end of the steam era (1960). And I dont wanna have any cars and locomotives from the later era's (Diesel and so on).

So please, can you give me the information, which lettering is the right one for my special era, and, if possible, are there any real "good" book(s) for information about this questions?

Thanks a lot for your help

Harald