Firstly, I should point out that I am not a big user of Files Forever, my answers are based on how I understand things to work, based on reading the information in the Panel and the wiki article on the subject.
I don't think you will see anything in the View Invoices section unless you actually had a negative account balance and your Files Forever proceeds were used to cover this balance.
As far as I know, the only way to view the history of Files Forever payments is using the Files Forever -> Billing History page in the panel. Use the dropdown control to select the month you are interested in.
The wiki article says the payments are handled the same as rewards payments and they usually vanish from the rewards section of the panel on the 1st and turn up in PayPal around the 3rd or 4th (depending on public holidays etc.). You should receive an email from PayPal when the payment has been received.
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