Underwood light was an accessory option, although pretty much not even mentioned after the early 70's. Those models at least had the screw holes and harness in place to simply plug in. By the years of these, neither were catered for, although not hard to add, either. But it also has 2, that's new, shaker specific! Normally just the one placed above dipstick on Pontiac engines.
The compressor guard isn't so much for safety as for stopping the fling of the end seal when it starts to weep. A common problem with some. That was an 80's addition, often Olds/Buick styles.
An aftermarket cover was popular with the Corvette crowd, lack of clearance, for working and oil. Can't tell if yours is a variation of that. The other was a mid-80's GM and so far my pics aren't showing it saved.
https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcTdMUhQ7yei171zzQ0_qj1Ax1K5BKzLcj_HyeRSex0orCl3QlGj_w91iMBH&s=10Also has the late cutaway overflow bottle, although never really understood why it was needed since the other fit. Obviously there was an extra option or arrangement that they thought it might be better with, or the smog pump bumped everything closer, like this one has. Maybe a non-smog 301 owner will recognise if the compressor is moved on this one. I can't recall.
