The strobe scope version is still available: https://www.harborfreight.com/timing-light-with-advance-40963.html https://www.harborfreight.com/timing-light-with

The strobe scope version is still available: https://www.harborfreight.com/timing-light-with-advance-40963.html https://www.harborfreight.com/timing-light-with-advance-4096... And I remember seeing a few of the rotary fishfinders / depth sounders still in use in the 1980s: https://www.ebay.com/i/322412202248?chn=ps&norover=1&mkevt=1&mkrid=711-117182-37290-0&mkcid=2&itemid=322412202248&targetid=915850928613&device=c&mktype=pla&googleloc=9002077&poi=&campaignid=9338046851&mkgroupid=94993845019&rlsatarget=pla-915850928613&abcId=1139336&merchantid=6296724&gclid=CjwKCAjwltH3BRB6EiwAhj0IUF2l-GY9A9y79k8kF83-JvzOR-qew2I3mqtLDS-CtBlaU3eIEY26rBoC0moQAvD_BwE https://www.ebay.com/i/322412202248?chn=ps&norover=1&mkevt=1...