That particular Columbus decal was used 1984-1987 but the frame could be slightly newer if the decal stock was not rotated. The presence of internal brake routing and a bridgeless bottom bracket shell are typical of late 1980s SLX frames, so the decal would appear to be legitimate. The fade paint with cross hatching would place it at the modern end of the time frame. So, lacking more evidence, I'd place this circa 1987.
European model names do not necessarily correspond to those used in America, but in the USA the SLX model was called the Aquila. This was normally followed by the group name, as the importer typically offered them with options of various groups. In this case, there appears to mix of manufacturers, groups and eras.
Edit: BTW, welcome to the forums.
Last edited by T-Mar; 05-16-16 at 08:41 AM.