As it effects the spacing this may be an incorrect application of scale to pre-scaled spacing values.

Fixed in dev code. Was being caused by the improper patch setup that was pre-scaling the 'engineSpacing' value, resulting in vastly out-of-whack spacing setups.

Will be updating the RO PR with the fix shortly.

Tentatively fixed in dev code; need to test/verify that it is actually fixed/working.

Apparently I was vastly over-complicating the calculations needed to derive the mount diameter for a given engine layout and engine.

This also appears to be because the engineSpacing value is being scaled by the enginesBasePatch.cfg patch file; that value should represent the spacing of the engine at its native 1.0 scale and engineScale is applied to it internally.