Hi ChinRey,
Thanks for your reply! Read someowhere about mesh transfer failures, but the lag meter and region stats seemed right (according to other posts I've seen, as I seed quite novice here) but I guess I will give it another try.
Not sure if it is possible to check that before final uploading... I will double check this time but I'm almost sure the preview in the upload window displayed ok
Regarding the use of meshes, yeah, that's probably wrong, lol, I've done tests replacing multiple wall sections with a single element (which is what I believe you're referring too)... but then I needed to wrap my head about textures and, a lot harder, LOD files, so I made this just using linked objects in Blender, so when I was doing LOD tests if I removed an inner face in the original it got removed in all instances
But you're right, once I get through the basis I need to think on optimization (right now plenty of available prims in my land so no hurries), thanks again!