The Age of Legends is a total conversion series based on the Star Wars Expanded Universe, from the aftermath of Endor to the defeat of the Yuuzhan Vong.
I'm upgrading lots of models from the old ICW version and the base game for the next release. The new ships here are from the Alliance mod and EvilleJedi's models used in the z3r0x mod.
Worlds that don't have their own native tech can build a 'Surplus Yard', which provides access to old ships like the Neutron Star, Marauder and Assault Frigate variants.
I'm curious, why didn't the New Republic just deconstruct all these old outdated ships for new ships?
Because if it aint broke, don't fix it? It's far more cost effective to retrofit these ships then it would be to build new ones. That said, the NR did eventually get into the business of constructing new ships, but not until it was propperly established and stable as a glactic power.
In the case of the Assault Frigate that's exactly what the Rebel Alliance did - turning old Dreadnoughts into Assault Frigates. But some old ships are still extraordinarily useful - by this time ISD Is are almost 50 years old, original X-wings are more than 25 years old etc. They all still serve a purpose, but you can reactivate the designs if you feel like it/want some cheaper, less powerful reserve forces.
A military force, especially one on a budget, will use something sometimes until it literally cannot be patched any more.
OK I understand now thanks for the replies.