How to identify NRC 45 ton boom and wheel lift???

[Boosttow]

When looking at trucks with no identification on them because of their older age, is there a way to identify the difference between a 35 ton and 45 ton fixed boom along with a super heavy duty or standard NRC wheel lift?

 

due to having to travel all over the country to look at trucks, is there a way to identify them via picture, any telltale markers or things I should look for that would show that it’s a 45 ton versus a 35 ton.