I have a late model T-18 that I hope to do similar things with. The engines are getting pretty rare though and are a bit pricey. It was interesting to know that ND Australia made the computers. The GT engines were never released in Oz though?
With your scans, the effect you see is called Moire effect and happens because of the line ruling used to reproduce newspaper images interferes with the scanning dpi. There is usually a "descree" function on most scanning software.