I'm currently babysitting a Medusa and happened to comment that it would look good with the original translucent targets that were fitted when these were new - these were brittle and broke easily and have been unavailable for a long time so are nearly always missing.
However, curiosity and the power of the internet led me to a pinside forum thread that had run for over 3 years and finally led to one enthusiast making a run of replacement repro targets. For anyone with a Medusa wanting it to look its stunning best this is your chance
(take a look at the last photo in the thread)
The thread also suggests that these are relevant to early run Elektras, although there is no mention on IPDB of this variant
The thread is here
https://pinside.com/pinball/forum/topic/bally-transparent-targets-what-machines-used-them
or you can buy the targets directly here:
http://www.langelius.com/
However, curiosity and the power of the internet led me to a pinside forum thread that had run for over 3 years and finally led to one enthusiast making a run of replacement repro targets. For anyone with a Medusa wanting it to look its stunning best this is your chance

The thread also suggests that these are relevant to early run Elektras, although there is no mention on IPDB of this variant
The thread is here
https://pinside.com/pinball/forum/topic/bally-transparent-targets-what-machines-used-them
or you can buy the targets directly here:
http://www.langelius.com/