Question:
Can InterForm400 merge spool files from JDE OneWorld?

Answer:
Sure, you only have to specify, that you want to print out *SCS spool files from OneWorld.

Here is how to do that in OneWorld Xe:
(NOTE: You should specify *SCS output).

ftp://ftp.software.ibm.com/printers/products/as400/iSeries/6250jdesoftware_draft.pdf