Timing Chain, and Alternator Repair Questions

[milli]

Hi, I am the original owner of my 1989 Toyota deluxe cab truck 4cyl 22RE.
I just had a major repair on my truck. $1800.00 The timing chain/kit /oil pan
gasket/ valve cover gasket were replaced among many other things - it is a long list.
one of my questions is: My new (well rated and recommended mechanic)
told me that the timing chain and all gaskets were not original to the truck.
I do not have any record of a previous timing chain replacement-nor anything
that was this expensive. I would have remembered a timing chain replacement
since it is major.

The recent work done on the truck - is less than a week old, and now the battery light and brake light will not turn off on the dash. I understand this
could be the alternator. The alternator on there now looks very different
than what I am used to seeing. ( I am a girl-so car issues are not my forte')

Any Ideas? or advice out there?
Thank you Milli