This just occurred to me as a random thought. With our old ships we have a choice of drydocking or dismissing them. Which leads to dismissing, as drydocks become full and we're left with not other choice than to dismiss them when we go to get a new one.
My suggestion here is, make it to where you can donate them to the fleet. Granted, no other player will be able to get that ship. However, it would provide another avenue for people to gain fleet credits. Sort of recycling old ships as salvage for the fleet ships.
Example of Rewards:
T1-T4 500-5000 Fleet Credits
T5-T5U 10000-15000 Fleet Credits
T6 20000 Fleet Credits
Fleet Ships return half the fleet credit cost to buy.
Now, since cash shop and reclaim ships are infinite. To prevent people from abusing this, it can be locked between 2-5 ships per day/week. Could go max 7 per week, locked at 1 per day.