that part does not look like an STL printer part but a part from a Stratasys printer (or that type) that extrudes plastic through a modeling tip.

Is that part plastic or the actual laser / light cured resin of an STL machine? STLs, unless the machine is very cheap that is being used or very old, have much higher resolutions that what your part shows. The plastic extruder types give results that look just like the pictures you posted.

The first image (the close up) is what is drawing me to that conclusion. In my former career we had several machines that we used in-house and that looks just like the plastic extruded technology from Stratasys.

Are the red parts the cured resin but just painted? If so, the resolution on the machine that was used is pretty bad. A good machine and 30 seconds with high grit sand paper will make the cured resin parts smooth like a baby's bottom.