The important point is that creationist argument is hit and run. You might ask a legitimate question -- and the possibility of forgery is legitimate -- but then you run away before anyone can answer. sometimes the answers are hard to find and take time.
Here's a link to some answers.
Here's something to chew on:
...the Eichstatt specimen has clear feather impressions (Wellnhofer 1974) and the Maxberg specimen has impressions in which the structure of the feather is discernable as being typical of that in modern birds (de Beer 1954; von Heller 1959; Charig et al. 1986). Not only that, the feathers of the Maxberg specimen clearly refute any possibility of forgery because they continue under the bones of the skeleton and are overlain by dendrites ...