I am curious if this is a bug or if I messed something up. I noticed you listed Tinkerer's Construct as being compatible with Armourer's Workshop but I can't get the javelin to work. Any ideas?

Here's my config:
# List of bows that can have skins applied.
# Format [mod id:item name]
#
# [default: [minecraft:bow]]
S:bowOverrides <
minecraft:bow

    TConstruct:longbow
    TConstruct:shortbow
    TConstruct:shuriken
    TConstruct:javelin
    TConstruct:crossbow
    TConstruct:throwingknife
 >

Sorry, 1.7/1.12 is no longer supported

try using the command to add it to the config. it may not be named what you think its named. please try this and let us know.