Nit-pick print quality question - just curious

[printbus]

The files are too small for what I wanted to look at, but here's what I was thinking. I've seen cases where a repetitive vertical pattern on the outside is caused by infill. What I wanted to do is upload the gcode file to the online viewer at gcode.ws and scroll up and down through the print layers, observing where the print head should be moving in straight lines and where it is zig zagging around for any infill. Try viewing the full file in gcode.ws yourself. The slider on the right side will move you up and down the print layers. The slider on the bottom can be used to view the nozzle movement for the selected layer. If gcode.ws shows the print head only moving in straight lines for the vertical walls on your print, you at least know the issue is something in your printer, not a slicing artifact. If gcode.ws shows an infill pattern in the walls, gcode.ws might indicate whether the infill pattern is at about the interval you're seeing. If so, try changing the infill percentage and see if the repetition interval on your print changes.

It's been forever since I've worked with slic3r. The settings summary at the end of the 2nd file probably answers the question, but how many perimeters are you printing? You might try printing with another one. Or try printing the external perimeters first. I think you're currently printing them after infill, which could help cause any infill pattern to show through.