I think that the fact that the van has had a reco motor installed devalues it more than side windows. The windows on that van are worse than useless, they don't help in reversing out of angle parks and deface the side of the van. Having driven both windowless and windowed vans as dailies for work vehicles and personal transport, having windows in the sides make it only slightly easier for reversing due to the height of the bottom of the window. They are usually too high to see anything smaller than a semi approaching, although once they saved the life of a moron who thought that they could walk across the back of a reversing car, I saw something out of the corner of my eye and stopped just before hitting her. Personally I like the look of a windowless van and if I was looking for a Sandman Van I would look at windowless before windowed. I would also want more proof than pictures of the paintwork and non standard interior before paying $40k for non original van like the one advertised, if it had the original engine and interior along with documented provenance I might be tempted.