Boards early 1984 are real 128 K, upgrades needed this "2nd floor"

Late 1984, Boards 128 and 512 are the same, only some chips more, so, no more "2nd floor", the design is included!

I need your assistance please: Is there anybody knowing which chip is the ram "F5" , I've got error code "Sad Mac 040001" with this kind of 2nd generation 128

and I would like to upgrade a 128K (design 630-0101) to 512, could you have any indication of the chips I do have to replace?

I could ask to uniserver, but I  realised that shipment  from France is same price as a new machine...

(apologise if I'm not "in the mood", it's my first Post...)

Happy New Year !!!