1ngram

As a technofool I don't know how to post photos and as a H0 modeller I don't have OO wheels.  Gibson's lists have close-up photos of their wheels.  Look there.

Obviously Gibson   And I write as someone who has in the past had an inordinate amount of trouble prizing ordered wheels out of them

  Still worth it in the end though

Sorry I forgot to point you to here: http://www.rmweb.co.uk/community/index.php?/topic/56339-gnsr-outside-framed-wagons/ where there is a photo of the flatpacks made up into complete models.

We started off with a full model, four sides, roof and all but no floor and only went to a flatpack because we couldn't get an acceptable model - I've a plastic butter container full of rejected models in both H0 and 00. If you can find a printer who can guarantee the quality you want on all four faces go for it but the "safe" option is to go flatpack because there is you 'only' need one face to come out right. Plus a one guy operation seems to take more care than a big firm like Shapeways where the guys on the machine seemed to have no contact with the PR etc people and just would stick it on willy nilly. Up to recently Shapeways would give you a voucher if the print "failed" so you could ask them to try again for free, but I hear they no longer do this.

" if doing a simple van, would a separate set of essentially-flat four sides/ends and roof be better (in terms of surface texture quality) than an integrated whole?"

This is what we did with our GNSR externally framed kit but Shapeways still couldn't get it to come out at an acceptable level of detail. We went to CWR and you can see a raw primered only (no sanding down or touching up) version of our kit on this thread from post No.16 onwards: http://www.rmweb.co.uk/community/index.php?/topic/56296-gnsr-4mm-kits-any-available/

We tried for over six months and several revisions of the CAD plus reprintings by Shapeways and finally gave up on them when they admitted (at last) they just could not get the quality we wanted on all faces of the model. We went to CWRailways who within two days had produced a far better product. I would advise you to contact them. You can see from their webpage the quality of the locos they are producing for themselves at present. http://www.chrisjward.co.uk/index.html