Putting rear derailler back on after shipping

[kellybikequest]

i recently shipped my bike and am trying to put the rear derailler back on. i notice when i screw it in, the B-screw is seemingly not lining up the way it did before. the general derailler screw does not seem to screw all the way in as well. i've attached two photos to show. any help is greatly appreciated

[cyclerUK]

If you haven't done so already then fit the chain.
I would assume if you turn the dérailleur into it's usual position that the "B" screw will contact the ledge.

Are you sure the mounting screw went all the way in before?
There appears to be some dirt in the exposed threads which may indicate that the screw didn't go all the way in previously.

Remove the dérailleur and check its threads for length etc.

If there is no play in the dérailleur where it attaches then I would say it's O.K.

I have just checked a dérailleur and there is about 6mm of exposed thread on it's mounting screw.
I also looked at my bikes and one with a replaceable gear hanger is thicker than the hangers on my steel frames.
this may account for the threads that show on yours?