There are some version 2.9 assets on the DLS:
<kuid:653172:100602> NP USRA 2-8-8-2 Tender
<kuid:653172:100677> NP USRA 2-8-8-2 Tender #4501
<kuid:653172:100864> NP USRA 2-8-8-2 Tender #4502
<kuid:653172:100870> NP USRA 2-8-8-2 Tender #4503
<kuid:653172:100865> NP USRA 2-8-8-2 TS12 #4502
<kuid:653172:100601> NP USRA 2-8-8-2 TS12
<kuid:653172:100676> NP USRA 2-8-8-2 TS12 #4501
<kuid:653172:100871> NP USRA 2-8-8-2 TS12 #4503
I also have these, but when I look at the config.sys it just credits Ben Neal at Subpar
www.steammachine.com/bdaneal
<kuid:674557:100368> NP Z-4 2-8-8-2 4503
<kuid:674557:100371> NP Z-4 2-8-8-2 4503 Tender
I am also thinking that TrainzForge may have some, as they have a lot of steam locomotives. Probably worth checking out, as they may be newer versions.
EDIT: I also found these on the DLS, they are version 3.7, and there may be more:
<kuid:327871:102751> Texas & Rio Grande Western 2-8-8-2 front bogey #2408 (14)
<kuid:327871:102755> Texas & Rio Grande Western 2-8-8-2 front bogey # 2416 (14)
<kuid:327871:102758> Texas & Rio Grande Western 2-8-8-2 Tender #2408
<kuid:327871:102752> Texas & Rio Grande Western 2-8-8-2 Tender #2416