Hi Floyd, welcome to WRT!
I'm also pretty new so take everything I say with a grain of salt.
You ought to be able to measure the case ID to determine the crystal size and then purchase one of either side of the diameter you think ought to work.
As to other parts, there are a couple of resources that will help. One is a website in Germany that will help with information on the movement. The other is a book (that I don't yet have) that seems to have a lot of information. Many of the vendors have this database available online and there are pdf versions that you can get on CD.
Looking here will give you a list of domestic (USA) resources for parts and tools if you haven't already found some.
I think relying on the "stripes" on the screw head is the issue.
If they're there, great but don't think that a normal screw head can't be left-handed and don't assume that the ratchet wheel can't have a left-handed screw either.
Actually, they did. This from the service manual for the 23 movement:
That was the advice given, in 1960 something. The "cleaning fluid" was Naptha, lighter fluid. These were watches you bought at convenience stores or the paper stand. They were worth less new than a watchmaker would charge to service them.
So, it depends on what Timex you are talking about but the poster didn't say, hence my throw away comment. Pre-quartz timex were a disposable that no watchmaker would consider working on. Now of course, those same mechanical movements have a keen following.
There's a bunch of really old Timex manuals, including this one available here:
A really awful URL but it still works, rather slowly.