Old St Peters in Rome was not demolished until the end of the 16th century, so there ought to be quite a number of engravings and artists’ depictions of it. I confess, tho, that I know little about early engravers, and so don’t know where to look.
The following item, from 1575, is by Giovanni Battista De’Cavalieri, and shows the drum of the new basilica rising behind the old portico. Thankfully the British Museum make it available online here, with the explanation “The ceremony of the opening of the Porta Santa for the Jubilee of 1575, with crowds of pilgrims standing in the Piazza San Pietro with the new cathedral rising behind the old one.”
It’s very interesting to see, all the same. That portico at the front is conspicuous in all the engravings.
UPDATE: Joseph Yarbrough has sent me a link to De Cavalieri’s book Urbis Romae aedificorum illustriumque on Archive.org here. This has marvellous images of the Roman monuments in his day (although not this print).