In April 2016, The Fuel Rats reached 10,000 successful rescues. To commemorate the event, Frontier Developments introduced an in-game Fuel Rat ship decal that was handed out for free to all players who had performed at least one rescue before April 1st, 2016.
This entitlement was done manually by FDev support, and was a significant piece of work, for which we are very grateful. However, this was a one-time event, and there are no plans at present for giving out this decal again.
In short - you pretty much had to be there. No, we don't think they'll make any exceptions. Sorry.