My weekend riding friend has a Synapse disc in a 58 from that time period. His has Ultegra Di2 shifting which has worked well for him. This era disc wheels were quick release, not through axle but I can’t say for sure if this ever led to any disc/rotor alignment issues.
If the Maddox wheels were the OEM ones, it might be worth it when you get the bike to take the wheels to a competent wheel builder near you & ask him (or her) to do a tension & true. While you are at it you might start fresh with new rim tape & new tires. Or better yet, budget for some new custom wheels built up that will perform optimally for your current weight and that are fast & strong enough to handle most everything you throw at them.
Your rear disc hub is most likely a 135 quick release disc type - there may be some deals on these of NOS quality hubs on eBay since this spec is being phased out. That size used to be common on disc cyclocross bikes from that era.
If you do build up custom wheels, I suggest a good aluminum rim that is tubeless ready such as a HED Belgium +. Then get tubeless valves & rim tape then have some fun & spec some fat 28, 30 or 32mm width tubeless tires & mount them up with some latex sealant of your choice then go enjoy amassing some biking miles!