After digging around, I found that there's a blueprint for bladewood, but doesn't seem to be one for Proto-Sparrowhawk. If the bladewood BP supposed to be dropping from somewhere? If yes, what about Proto-Sparrowhawk?
The prototype Sparrowhawk and the prototype Curse are one-offs; you can recover the lone wrecks I placed in the sector, but not produce more. That's mainly because of how powerful/unbalanced they are; the balance mechanism for a ship like either of those is for you to only have one, and when you lose it in battle, it's gone forever. If you could make fleets full of either one, you would, and the game would get less challenging and interesting. They're flagships, not building blocks for an interesting fleet.
Something like the Bladewood, on the other hand, is more powerful, but that's because it's a relatively balanced capital ship, not an unbalanced destroyer or cruiser. So it can be a production item.
You can, however, make your own blueprint pack for it if you so desire (add a 'rare_bp' tag to the skin file and it should show up in salvage), or use Console Commands:
addspecial ship_bp istl_stormkestrel_proto
I'm not opposed to having some method of outputting (single) replacements for destroyed Curses and Sparrowhawks at some later date, but right now it's pretty far down the to-do list. If they were more common, I'd also rebalance them to be less powerful.
