Sansui SP-2500 - Keep Original, or Modify?

In-looking (locally) for a Heresy-sized, high efficiency floor speaker (little kids == no towers, stands), I've come-across a 99% mint condition pair of SP-2500s, and for a song. Admittedly I am not one to keep things 'original', if quality is being sacrificed. I was thinking of rebuilding the mid/high section with new mid drivers, and a ribbon tweeter (and removing the HF 'lens'). Some crossover work, as well, of course. 

Does anyone own SP-2500's, and have you modified them in a way that is to your liking? Or would a guy be better keeping these, as-is?

For me I would not think about buying a pair of 1970s loudspeakers, every component would be suspect. They WOULD make a nice cabinet for a DIY project but it's easy to blow the budget doing that. What the heck, go for it. 
Unless you know a lot about crossover design, you shouldn’t be swapping drivers. I owned a pair of 2500’s for a couple of years for my garage, and I don’t think that they’re worth a lot of fuss.
Dude, if you are going to do that, you are only keeping the box. Um, sure, but do you know how to do speaker design? It's not just driver swapping.

If you really want to build a speaker I strongly suggest you build from a kit instead and leave these for some one who wants them as is.
I have a pair in my speaker collection! Mine are staying unmolested as examples of 70's Japanese "kabuki" sound! I say leave the drivers alone - just upgrade the crossovers with modern caps and inductors. Otherwise you will ruin the "flavor" by changing the drivers!
Buy something else, they were decent back in the day. Too many drivers over the same frequency range = unclear/fractured sound. If you want  3-way, go with 3 drivers.
Or at least buy the speaker cookbook first so you know what you are in for.
Why not get Heresy's? there's 4 versions now and so many upgrades available form the likes of Bob Crites etc that you can tailor the sound to your liking. not to mention they made a ton of them so their everywhere.  Add a sub or two and your in happy mode.

I'd stay clear of anything Sansui made that had speaker drivers in them, they are not known for their speakers, and I'm a big fan of Sansui. Generally most vintage speakers are not up to todays sound standards of course there are a few exceptions but generally the mass market speaker from that era are all a let down. 

So many modern designs that are way better for similar money. 
"...I'd stay clear of anything Sansui made that had speaker drivers in them, they are not known for their speakers..."

Back in the day, they were well known for their speakers. Not my cup of tea but very popular. 
Thanks for all the input. y'all. It is eye-opening to see such an array of opinions.
Reason for not getting Heresey's, Model 5's, etc., is kids and money. I'm still several years away from having "nice stuff", again. So $3k for something that I might wake-up to having been markered all over? Nope. $300? That I can live with.
I would keep the low-end; it would just be the mid/high array that gets a (modest) update.
And yes, this would be a hobby/project speaker, of sorts.
After understanding your situation, I will change my no vote to a yes. Before I got into Altec, JBL and ESS, a friends Dad had some Sansui 2500's and I thought they sounded good compared to what I was use too. Those lattice grills will help protect the drivers from prying fingers, especially if the $$ is right. The only alternative I can think of are some pro JBL's with metal grills and black cabinets, but the wife would certainly frown on this.