Because the 575 and 580 use different CRTs, they also have different analogue board circuitry. On the other hand, most of the trickiest Takky work involves getting the Color Classic's 512x384 display circuitry to run at VGA (640 x480) - which the 575 and 580 both do natively. So it might not actually be that tough.

So if you're thinking of doing this for the fun of the process, I say go for it. But beware that it's a fair amount of work; there are lots of things that can go wrong; and while most mistakes are fixable, the CC-hacking community is a lot less active than it used to be so quick online help is not nearly as available as it used to be. (For example, I've forgotten probably half of what I used to know about this stuff - I've modded about a dozen CCs but the last one I did was around 2005...)

If, however, you're thinking of doing this for a practical outcome - i.e. a simple, more usable upgrade in CRT/display quality - then I'd say it's not worth the trouble. In that case I'd recommend sticking with the stock 580 and keeping your eyes open for another 575 (perhaps one with working logic board and busted CRT).

Either way, good luck and let us know how it works out! :beige: