The VW steering design is not exactly geometrically correct, but if you have checked the linkages and they are tight, the box may be the culprit.
A new steering box is the best bet. Keep in mind these cars were built from donor cars…who knows in what condition or mileage.
I sold an NOS German made box I had a few years ago, but I think Brazilian made units are all that is available now. I bought two from a local VW shop going out of business. I used one on the car now called Angelica (Bill Collins).
Good idea to buy German made parts for the VW stuff as much as possible. The used German stuff is usually better than the new Brazilian stuff in most cases.
How far does the sterring wheel turn (one way) before the action is transmitted to the front spindles?