Today, after exactly 10 months, I’ve finished the Jon Pertwee era.
I must say it was quite the ride and the quality of each serial was pretty solid. I still prefer Hartnell and Troughton to him, but I’ll sure miss Pertwee as the Doctor.
And now, off I go with starting properly the Tom Baker era!
Good luck!! It’s a long one!
Indeed, if it took me 10 months to finish 5 seasons, I wonder how much it’d take to watch 7!
You could make it seven years just for the authentic experience 
You could also listen to the Short Trip entitled The Authentic Experience for the authentic experience (although it has nothing to do with any of the first four Doctors 
)
How goes the progress?
Started the last serial of Season 15!
Invasion of Time is one of my favorites. It’s just a lot of fun and watching the interactions between the Doctor and Borusa are fantastic.