ok so i spent some time testing this out and it works!

first some of you are probably aware that you can generate a new seed for your ship with this tool

http://nomansskymods.com/mods/seed-changer-shipmultitool-changer/

BUT it does not allow you to change ship classes (fighter to trader)

you can manually edit your save file for that

you must replace the 3 save file but instead of just changing the seed of the ship you will change the entire bracket as default

Fighter

"CurrentShip": { "Filename": "MODELS/COMMON/SPACECRAFT/FIGHTERS/FIGHTER_PROC.SCENE.MBIN", "Seed": [ true, "0x8B52A80894AFB38F"

Shuttle

"CurrentShip": { "Filename": "MODELS/COMMON/SPACECRAFT/SHUTTLE/SHUTTLE_PROC.SCENE.MBIN", "Seed": [ true, "0xF73F8B835F7506E"

Science

"CurrentShip": { "Filename": "MODELS/COMMON/SPACECRAFT/SCIENTIFIC/SCIENTIFIC_PROC.SCENE.MBIN", "Seed": [ true, "0xABF925A00596C953"

Trader

"CurrentShip": { "Filename": "MODELS/COMMON/SPACECRAFT/DROPSHIPS/DROPSHIP_PROC.SCENE.MBIN", "Seed": [ true, "0xE438D0D4F4AB9AAA"

this will replace the entire body and class and you can then start generating seeds for that class with the seed tool!

hope this help someone!

Note your ship will retain the same amount of slot and all it's upgrade and cargo only the model of the ship will change!