It would seem curious to me that only one given dimension is to four decimal places. The rest of the dimensions seem to be much more run of the mill.
I would draw out what you know and see if it gave some more rounded lengths.
I would drop a vertical pipe down first centered on the base plate and then using that same centre point rotate the pipe 60° and then 'push' it through the base before cutting a bit off the bottom.
That's also how I would interpret it - 60 deg. from vertical.
I'd probably have dimensioned it at the other end as 30 deg from the 1.25 dimension leader on the centreline. But TBH that's all horrible dimensioning. There is nothing to position the boss (other than being on centre) and the 2.5 goes to the centre of a lug/hole you can't even see and have to infer from the '2x .38 THRU'.
EDIT - I can see the lug/hole in hidden detail now that I'm on another device.
When dimensioning anything you should think of how the person making/inspecting it will be able to measure it.
The MEASUREMENT variable merely sets which hatch patterns and linetypes are used - metric or imperial.
Drawing units for new drawings are controlled by MEASUREINIT
Just to confuse matters, I mostly draw in metre units and present drawings at 1 to 200 scale. I find the imperial linetypes are easier to use at a linetype scale of 1.