To mod or not?

I just recently (2 months ago) inherited a 1992 Miata with 39K miles on it.  This thing is pristine.  The only things not original are the tires and the battery.  It runs great.  I have a blast driving it and would love to get more out of it.  I can't decide whether it's worth it to add some hp or just leave it as is considering the year vs. mileage.  Any opinions?

Hi Hungus and welcome to the forum.
Sorry it took so long to reply.
 
I would say that if you can add some bolt-on zip for your enjoyment, why not?  Keep any original parts you replace so you mught put them back, or offer them to any new potential owners.
 
I remember when these early Miatas were new.  Having owned a few MG's in my day (<<< whatever that means?) I wanted one. 
The biggest complaint at the time was that not only did they look very retro, like a British roadster (a good thing,) but that they were also under-powered like one too.  A few careful touches could make it a better running car for you in these more modern times.
 
Just my .02.
 
 

I say keep your foot down and have a blast. 39K miles on a '92? That, my friend, is LUCK.

Only 39K?  WOW!  UPGRADE!!!
 
Easiest things in the (motor) world to install: intake, exhaust, headers.  Too easy and fun not to upgrade!
 
http://www.gripmotorsports.com/dl.aspx?pnd=Mazda-Miata%20MX5-1992
 
http://www.nopionline.com/nopistore/dsp_pcsall.cfm?vmakeid=220&vmodelid=080&vcatyear=1992&vtype=A&vcatid=1&vTitle=1992%20MAZDA%20Miata&vn=0
 
http://www.sportcompactonly.com/Mazda/Miata/makes_v-146_vy-1992.htm
 
http://www.modacar.com/products/Mazda/Miata/MODAHEA