Originally Posted by
jaberwok
Hi and welcome to AUGI.
first off - you have some dimensions missing - especially the horizontal distance between bores (=50) and I doubt that it would be made to look like that anyway.
However -
assuming that you know the basics of isometric, I'd start by constructing the plan view so that you can measure from it.
In the isometric portion of the attached screen shot, red = centre lines and blue = the major holes in the base surface and white = the holes and the bosses at their top surfaces.