Paolot, you will discover that it is indeed possible to "refit" "fighters"
You will soon thereafter discover that, though it is _possible_, It is very VERY inefficient.
making new fighters of the new class is only about half a million times quicker, easier, and cheaper.
Thank you, Steve.
Someone said: "
This is my mistake, let me make it good".

In real life, to arrive to the production of new models it's lengthy, expensive and sometimes ineffective (the B-52 is still in operation because of this). So, it is preferred to evolve, upgrade and expand the existing models, and I prefer to mimic this approach.
I'm adding slipways to the SY, to be able to convert one squadron at a time (having enough resources), not a single fighter one by one, to save time.
Then, maybe I'm comparing numbers not correlated, but I see the "refit details" and the cost for a "new fighter" (see the attached images), and the first ones seem rather smaller than the second ones. Am I wrong?