Smoleń, a variant of smoluch, is derived from smoła (tar, pitch) but used figuratively to mean a grubby, soot-streaked slob. In the olden days it also meant a scruffy drunk and in the hunting world -- a boar wont to bed down or hide in a den covered by coniferous branches. It could have also derived from such localities as Smolany, Smolechy (Tarville, Pitchly) et al. A tar-maker incidentally is a smolarz, but it's not inconceivable that one got humorously dubbed Smoleń.
Świerk is a spruce. Possible toponymic sources: Świerki, Świerkocin, Świerczyna (Spruceville, Sprucewood).
