Finding 3 mistakes in an engineering drawing

[Johnny26]

Homework Statement

There are 3 big mistakes in this drawing and I would really appreciate if anyone could help me find out exactly what those are. Thank you.

Homework Equations

Since I am new to engineering drawings, I can only make assumptions and would really appreciate if I am corrected rather than mocked.

The Attempt at a Solution

As far as I am concerned
1- The vertical line should be of a different format as it would not allow rotation if they are the same.
2- It is unclear what the dimensions are (whether they are in millimeters or centimeters etc)
3- The angles should have some negative deviations as well in addition to positive ones (if this one is incorrect, kindly explain it to me why)
4- (=210=) Is this a valid format as I am pretty sure it is not.

 

[CWatters]

Only had a quick look but:

1) the length is 420 on the drawing but "L=364" on the Dimensions block at the bottom.
2) I've not seen =210= used before but if it's a valid notation why isn't it =420= just below?
3) Date/issue/version number?

 

[phinds]

Uh ... one is that you misspelled mistakes