its not exactly brain surgury.. its a couple of nuts and screws.. its a matter of having the correct cleaning solvent and the correct grease.. and having a feel for “how the parts” are put back in.. in which order and why.. and why certain things are put in at a certain angle.. and THEN adjusted into place to be tightend down.
once you do a few then they all seem to be fairly alike.. its the knowledge of doing the few to get started.
plus parts aren’t as available like they used to be.. neither are reel repair shops.. and models change much faster now then in years gone by.
for almost 30 plus years the gears were the same on a “Mitchell 300”.. the bail changed over the years but handles and other parts remained the same for over 3 decades.. the same with the old Zebco’s.. until the industry decided change made “more money”..
I am not saying that improvements didn’t need to be made..
But I find very few reels that are a smooth and dependable as my old Cardinal fours.. or the black C4..
good luck in your quest.. oh and this is coming from a guy who’s first job in the world was Easterling’s Rod and Reel Repair at the age of 16 in 1972 and I remain friends with Louis to this day.. 
