A technical upgrade does not automatically increase value
“Upgrade” means an improvement relative to a goal: reliability, noise, ergonomics, power, tuning or features. It does not automatically mean higher market value.
A modern pickup, speaker or component may make the item better for your use while moving it away from a configuration sought by collectors.
Before changing anything, define the goal and ask whether a reversible solution exists. Also consider the cost of returning to the previous configuration.
For the broader economic assessment, use Muviber’s dedicated used-gear pricing and valuation guide.