Welcome to the forum. Please add your location and your bikes' models and model years to your profile so that you don't have to remember to tell us every time and we don't have to keep asking when you forget (see Forum Settings link in my signature).
And welcome to the world of antique vehicle ownership (As you may already have figured out, they own us, not the other way around). Your bikes are about 4 decades old and all good intentions aside may or may not have had all of the maintenance necessary to keep it safe & reliable so it is highly recommended to download the Factory Shop Manual for your model (available through the CX Wiki - link in my signature) and go through all of the service procedures, regardless of whether your bike has reached the specified mileage.
I'd go over the customized one extra carefully because you never know what the Previous Owner may have missed or just not done well enough.
NOTE that we almost always recommend referring to the FSM instead of one of the aftermarket books. The factory books for this family of bikes are particularly well written and organized so unlike the FSMs for many other bikes you can actually understand what they are telling you to do instead of having to rely on what the aftermarket book's author thought the factory book meant.
I also recommend looking on all rubber parts with suspicion because rubber does not age gracefully. Check the date codes on your tires and replace them if they are over 5 years old no matter how good they look & feel (old rubber simply cannot flow around the irregularities in the asphalt well enough to grip, especially if it is cool or wet). If your bikes still have the original rubber brake lines (should be replaced every 2 or 3 fluid changes = 5 or 6 years) I recommend shopping for modern stainless braided ones (they last practically forever and double the life of the fluid). And don't forget things like the rad hoses and the boot between the engine and swingarm (they can crack on the bottom where you don't see it).
The customized one looks nice at first glance but I see a few things that I'd want to correct.
The missing front fender and unprotected rad are a problem waiting to happen, not to mention that there is a stay inside the fender that acts as a fork brace so the handling can be affected by its removal too. (I won't even get into how much you will wish for those fenders the first time it rains when you are an hour from home)
I don't see any side reflectors on it (the ones from the rad side plates on the stock bike are missing too). You would probably never get a ticket for not having them but do you really want to give some idiot in a car an excuse to claim he couldn't see you at night?
I don't see any turn signals either. The US DOT requires a 4" spacing between a turn signal and any other light that is on while it is flashing (any closer and it is too hard for other road users to see the signal) so signals built into the headlight and tail light aren't legal unless the main light turns off while the signal is flashing (doesn't sound like a good idea to me).
BTW: The best advice anyone can give you about customizing any vehicle is to get it safe & reliable in more or less original condition and use it for a while before you start making any changes so it can tell you what changes it needs to make it do what you want/need better. That approach almost always results in something you actually want to keep and use but making changes based on style or on what someone else (who may or may not really understand how the changes affect the way it works) has done often results in a piece of expensive yard art that you can't stand sitting on for more than a few minutes and might even be dangerous.
