Will Fraser;
Fairly certain I see three attach/systems. the forward hole (missing the pin) is 'shading' a bulkhead cap similar to the most aft structure. All three towers seem present, though what would be the port side of the forward carriage is in darkness.
'k, I can take a further look by bringing the shadows up a bit, thanks. We'll know soon enough I'm sure.
BigHitDH;
I have access to a 340/330 AMM and tried for a while to find drawings of these structures but ran out of time. The AMM is not the easiest nor friendliest document to navigate in so it is very time-consuming.
I strongly suspect the boxes are near or perhaps part of the THS structure but can't say so.