I have a old Skidoo Single Cylinder Engine Block, and Flywheel, I need to figure out the Bolt Patterns, and Timing Degree's.
Well, yes! Im explaining the concept using a 2D drafting program, say AutoCAD.
-> Import the photo in the CAD application.
-> Next, take a dimension for reference that you already know to be accurately measured in the real world part. You need at least 1 dimension as a starting point from the real world!
-> Next part is to draw a line or circle (or whatever) with the known dimension, inside the CAD application.
-> Move->Rotate->Scale the reference geometry you just created so that it most perfectly aligns with geometry in the part picture. Say you measured the ID of the central hole. So make the same dia circle in the CAD application, and overlay the image so that the circle aligns nearly perfectly with the ID periphery in the image. Scale and move the circle or scale, rotate, move the image whichever suits your use.
-> Next create other entities to take measures off of. Say, the centrelines for the hole radially outward.
-> As a last step, you can use the CAD application's inbuilt measurement/inspection command to measure distances, angles, diameters, etc. between such reference geometry that aligns perfectly with the part image.
I hope this helps you.