It would make more sense to cover the accelerators in armor, or just conceal the whole thing in a giant dome, but yeah, then they wouldn't really be recognizable as Farstrikes, and that's no fun. I don't have any particular reward in mind either, but if you're asking... lance research bonus, maybe? Or just some production?
Anyway, ship histories:
Red Robert
Built 712 years ago in Calavar itself, this ship was originally a freighter named the Gliding Swan. For the next 170 years her career was largely uneventful, hauling cargo around the subsector. Then she was captured by an ambitious pirate captain calling himself Red Robert. He rebuilt the ship for combat, renamed her after himself, and gave her to a subordinate. That subordinate proved to be less loyal than he had thought, and the ship spent the next 288 years passing through the hands of one pirate or another. Eventually, she was captured by the system defense force of Markuk, a civilized world in the northern reaches of Lativa subsector. She was then added to the system's modest fleet, where she remained until the increasing chaos of the subsector brought down Markuk's government, and the ship fell into pirate hands again.
Carnival Dagger
It's not entirely clear where the Carnival Dagger was built, but she is certainly not native to Lativa Subsector. Her design indicates that she began life as a troop transport - probably Khornate - and the surviving logs suggest she originated somewhere to the galactic West. At some point she was refit to launch boarding torpedoes (though none are now available and she has been making do with Yttreum's make). Whatever her origins, she was brought to Lativa in the early stages of the collapse by her current captain, Jandik Orevan, intending to pick over the bones. Even he's not entirely sure how that lead to his current situation, but it has proven profitable enough.
Iderak Stallion
The Iderak Stallion was pulled from a space hulk near the feral world of Iderak by an unusually large and well-organized pirate gang. As the freighter had already been armed by some unknown ancient owner, they repaired her and added her to their fleet, where she plagued local shipping for over a century. Eventually, the gang dissolved in a flurry of infighting and betrayal, and the surviving captains went their separate ways. One of these captains made off with the Iderak Stallion and two other ships, but because she didn't have enough men to properly crew all three, she sold the Stallion to Yttreum in a back-alley bargain for an unspecified sum.
