Lemme quote straight from the book:
Page 305 CRB
As the PCs go on adventures and gain experience, they needan increasingly powerful starship to face tougher challenges.
When the characters’ Average Party Level increases, so does
the tier of their starship.
The PCs receive a number of Build Points equal
to the Build Points listed for their starship’s new tier – those
listed for its previous tier, which they can use to upgrade their
starship. For example, a group whose APL increases from 2 to 3
receives 20 BP that the PCs can use to upgrade their starship.
This could represent salvage gathered during their exploits,
an arrangement with a spacedock, or called-in favors from a
wealthy patron. Some GMs might require PCs to visit a safe,
inhabited world before they can spend these Build Points, but
this shouldn’t be allowed to impact the campaign too much
So the answer is yes, but as an abstraction - and only after the APL goes up.
They don't need to instal the exact same stuff the Iron Rictus had, nor can they go over their BP budget only because they are stealing stuff from undead terrorists.