Nasty, very nasty :( :(
The problem with modifying a filter like this (with a separate insert) is the huge force trying to force it out....
Assuming a 50 mm ( 2 inch) basket diameter.... and 9 bar pressure.... the total surface area at the bottom of the basket is about 3 square inches.... 1 bar is 14 lb per square inch so 9 bar would be 3 * 14 * 9 (very approximately) or about 380 lbs - back to metric - over 170 kg!!!!
Sorry about the imperial - I just know it better ::)
You will need to leave quite a large lip to retain 170 kg or it will just force its way out!!!
Are you sure you cant get a normal basket (possibly from a different brand) which will fit?
EDIT: by the way if your filter is larger than 50mm those figures are even worse.... and many vibe pump machines run 11 bar or even higher.... even worse still :(