OK, sounds like the ignition has already been serviced, great! This engine should have solid core plug wires, so yes, they should be replaced if someone put fancy automotive plug wires in there. I think the correct wires are 7MM diameter though.
And yes, keep that mixture at 16:1, even though 24:1 may actually be the recommendation. That engine has some plain bushings on the wrist pins, the extra oil is a good cushion, and a good running motor won’t smoke much or foul the plugs (unless endless trolling is your thing) using the 16:1 mixture. I LOVE the smell of two stroke smoke and plugs are cheap!

Welcome!!
You have found a very nice motor at 67 pounds it packs hp. Tip on pulling the flywheel, use a harmonic balance puller but NEVER run the three screws too deep into the threads, It will hurt the magneto parts. On the gearcase be sure to replace the shift shaft O-ring, That guy always leaks.
You will find the gearcase straight forward easy to service. Look at the shift dog on the prop shaft for damage. Look for fishing line on the shaft too. If that seal is wet it must be replaced as well. I’m sure everyone has covered most of it so I’ll go. Just be sure it has compression before putting any money in to it too.
BE SURE to read the inside hood instructions. It has the correct oil mix written in the instructions, one quart of premix oil to five gallons of gasoline. I cheat, I own the same motor & have read it too. Equals 20/1 ratio.
HEY PAPPY, What prop were you running?