Another progress update on my RepRep 3D Prusa Mendel. After digging into the laying issue, I narrowed it down to a likely slicing issue. And, after a lot of research I was able to find the specs I needed for the particular hot end on my printer (a no longer supported version from Makergear).
The problem was that the layer height was to tall for extruder nozzle diameter, creating the gaps. Armed with the specs, I reconfigured Slic3r and the results are clearly better!
There are still issues. I think I’m pushing too much filament through and might need to tweak the temps.