As a side note, we could extend this and say that something can gain a use-value as part of a historical process, right? ... The magnet never changed, but through scientific development became useful.
Yeah very much so.
For example a lotta the aim of "production" in consumer societies as we have in the core is to make basically anything gain more use-values so there's more opportunities to sell stuff and more possibilities to get higher prices from induced scarcity.
This ties into Marx's point ofc about stuff needing to be an object of utility to have value. Much as, if something is no longer useful it is no longer valuable, if something is suddenly useful it is suddenly valuable.
I'm doing fine (finished reading the chapter) but as quarrk mentioned the readings be announced more in advance would be helpful.