There are no kits for making watches. There are kits for clocks. Sattler makes a kit but it is very expensive. If you search the web you will find a variety of clock making kits and sites. Many members of the NAWCC do clock building as a hobby.

To make your own watch from scratch requires a lot of skill since you can't buy ready made parts you would have to cut gears and all that and that is hard and as the parts get smaller the harder it is. The Timezone watch school is for learning the basics of how a watch works and how to take them apart and put them back together again and do minor service. I've taken both courses.There are some people who have access to a proper lathe and have constructed their own watch by buying a movement and making alterations but you have to really have some skill to do that.

As far as the pocketwatch situation you should never take any mechanical timepiece to a watch repairer unless you know he or she is competent. Most experienced people are getting to an age where their skill is deteriorating and anyone who learned the trade after the mid 80s shouldn't be let near any mechanical timepiece. There are precious few competent people around who can do any repair jobs on mechanical timepieces. If you have one near you your the luckiest person in the world and should run out and buy a lottery ticket.