Advice needed (which model, any restoration tips)

These watches do have some monetary value, probably a few hundred euros, but it is very difficult to provide an accurate estimate without much more information. Is the watch gold plated, gold filled, solid gold? What is the case size? What movement is inside? You can look at eBay sold items to get a general idea, but I would encourage you not to worry to much about its value. It's a nice watch, and it has value, but it is not going to make you rich.

More importantly, it has significant sentimental value as an heirloom. This particular example appears to be in good condition, and the quality of Omega hand-winding movements was very good in the 1960s. If you like this watch, and intend to wear it, I certainly think that a movement service, new strap, and crystal polish would be warranted. Find a local independent watchmaker with experience working on vintage watches. Make sure that you tell him not to polish the case at all. If mechanical repairs are needed, he should use correct and authentic parts within the movement. Tell him not to replace or tamper with any other original parts, with the possible exceptions of the crown and crystal, which are likely not original anyway. If the crystal is cracked, it should be replaced. If the damage to the crystal is just superficial scratches, they can be polished out.