Terry,  There is an online STL to OpenSCAD convertor here - https://raviriley.github.io/STL-to-OpenSCAD-Converter/ Generates an array of points which are downloadable as a .SCAD file. Works a treat, don't bother trying to edit the points, just generate the model and perform any other OpenSCAD operation that you need. I've been trying to tweak the JavaScript on my offline version to improve the usability of the output as its a non-Line feed delimited character stream that makes the OpenSCAD editor creak. I'm getting there :-). In the meantime I just <include the downloaded file> into another OpenSCAD file, then its all good. HTH Roger.