At the top are 2 x $25 showing the old 9/16" and newer 1/2" inserts. Note the shape of the 9/16" insert. The $25 denom was the only one that used the 9/16" size.

Here is another useful piece of info. ALL Christy and Jones H&C chips made by Burt had inserts in the same shape as the 9/16" on the Borlands. All PS chips have inserts in the shape of the 1/2" inserts. (Regardless of the size of inserts - I am speaking of their shape not size)

Below are a few chips with 'varying width' inserts. The El Rancho is probably the best match for the one on ebay.

Finally: NOTE that if you measure the inserts with a rule, dont expect them to be 1/2" or 9/16" or whatever. You have to compare them by shape not size. There is quite a tolerance in size. I had to send comparative scans to several Borland collectors before they understood what Jim B and I were talking about when we first posted these details some months back.