hey Edge, welcome to the LTG. sounds like a keeper and I think 700 is a fine price if in good condition as you say it is. the C will be for cherry stain top as you state, as I cannot imagine that being a cutaway.
Yeah, 'bout a year too early for the world's first cutaway dreadnought according to my increasingly feeble memory; those were D40's in any case.
Cutaway D25's not until at least a couple of years later; "C"
was the code for Cherry in '75.
Edge re your original question, I can only recall one member here who didn't like the sound of a spruce-topped D25
enough to keep it, and I think dozens who've ""bonded for life", myself included.
That formula of D25, spruce top/arched back, was the most popular and longest-produced version running from about '74 all the way to close of Westerly in '01.
In '97 Guild said more D25's had been sold than any other Guild and given ever-decreasing total overall production volumes since '01, I suspect that's probably still be true.
I like to say "read between those lines".
I consider mine to be one of the most versatile guitars ever produced, you can do everything with it, and some things, rhythm playing in particular,
exceptionally well.
It's the magic of the arched back.
And it's not as if there's a particular era that was prone to specific problems or anything, with those, it's just the same things you'd look for on
any(in this case) 45-year old guitar.