They are both simple 2nd order filters with cap and coil on each.
A lot more engineering went into the drivers back then to make them well behaved even with simple shallow slope filters.
Modern film capacitors are more transparent to signal than 1980 vintage film caps, so those are ripe for upgrade. I like Jantzen Superior Z, they are good value and performance, imo. Notice I didn't say it will "sound better," because the old caps may have been selected specifically to hide certain sonic flaws that the new caps might reveal.
If any caps are electrolytic (liquid) caps, then they are too old to use and should be replaced.
The stock coils are probably fine to reuse. Upgrading them might lower the DCR which can affect the filter function slightly, but sometimes that is a good thing especially on bass where lowest DCR is desirable for better electrical damping from the amplifier. If you get bigger gage coils and it sounds off you can add resistor to bring DCR back up.
If there are any attenuation resistors in the xo or on the drivers those can be upgraded with Mills wirewound 12W of same value as the originals.
You can post a picture of the XOs and we can tell you if they are electrolytic or film caps, magnetic core or air core inductors, etc.
Pay attention to the "cascade wiring" schema described. If your speakers are wired this way, then stick with that.
If there is no acoustic damping (stuffing material) inside the boxes, they might benefit from adding a small amount, but keep it away from ports. If there is old stuffing that's still OK, just reuse it. The amount of stuffing is engineered, so replacing it with different material ideally requires testing/measuring/listening, etc.
