Sofa chair ID and reco  

Am I wrong?
Didn't you imply these were your parents, and you purchased them for $300.00??? If this is the case and you bought them from your parents estate perhaps you can haggle,with your sibs. Been there, done that. Worth asking anyway..... I too love the pieces. I say, 'soldier on'...

Damage
Re-reading your post...Sounds like you need to go after the folks with the glue.....

Hazelnut...
They were my parents. I paid $300 to have the sofa (and ultimately the chair by virtue of the fact that I can't put the legs where they belong) butchered.

Nix my idea about a hacksaw;...
Nix my idea about a hacksaw; the legs are inset to get the right angle.
Get a big monkey wrench from the hardware store. Wrap the leg to protect it and wrench them off. If you've never used a monkey wrench before note that torquing with one side up tightens the bite, which is what you want, while the other way loosens the bite. One of those pieces of hardware will unscrew from its partner and then you can extract the rest and de-glue or replace as necessary

.
I'm a bit confused now but if I called any of your family members fools, my apologies.
Good luck with it, it boggles the mind.

money wrench
game on. i'm going to try it! thanks, Leif!
Hazelnut, don't worry, my family is wacky but not that much 😉
thanks everyone!
Will get back to you on the wrenching - not sure what torquing means exactly but I'll google it and possibly try a dummy first.

I would forego
any metal wrench and opt for a rubber strap oil filter wrench. Also, work the leg from as close to the frame as possible so you don't split it or snap it off.

so...
I called the place that did the (cough!) work yesterday. The owner emailed to say, "yes, I remember the sofa and that you weren't happy". (keep in mind I didn't know what the problem was at that time). As she remembered, the one leg that had broken, the metal threaded screw was replaced with a wooden dowel. She believes the metal screws are still in tact on the other three legs. She offered to pick up the sofa in August and get all the legs off safely. and do the switch with the chair, etc. Not sure this is the way to go, but I did pay $300 and she seems to understand the problem and willing to make it all right. Will keep you posted and thanks again for the feedback and support. (are you thinking I'm absolutely mad to send the sofa back for more torture? I just can't imagine myself with a wrench and wet towels - I could end up doing more harm than good).

Wow. If these people were a ...
Wow. If these people were a tire shop you'd take your car in for new tires and end up with bicycle wheels and bicycle brakes.

Try Suggesting
Try suggesting to the glue culprits a full refund or you post the name of the business on the forum (kidding, kidding..kind of)

I think it's worth a shot, BUT...
...get it all in writing what they are are going to do and how they will do it and what the outcome will be, and what, if anything, the work will cost (hopefully they are agreeing to no charge at all). You sign it and they sign it. Then you do a thorough examination of the work before you sign off on it again. Also, obviously, measure all the legs before you take it there and measure them when you pick it up. If you know ahead of time which legs belong where, then number them on the tips or on painter's masking tape.
Cover ALL your bases, in other words! Do not leave them any outs.
If worse comes to worse and they break a leg or two, the legs can always be replaced. It's not the best outcome but it doesn't mean that the pieces are rendered worthless and nonfunctional. (Oh, and put that in your written agreement, too--that they agree to replace any parts that may become damaged while trying to undo the mixed up legs, with the same wood species, etc. If they so much as raise an eyebrow, explain to them--politely but firmly-- that not only do these pieces have significant dollar value as vintage mid-century modern furniture, they have great sentimental value to you because they have been in your family for a very long time. Double whammy.)

thanks for all the tips
I'm going to get a second opinion. Leif is right...why would I go back? Thanks so much. I feel that I may be able to get this sorted! Hope you all had a great weekend.