I bought a PC 7539 for handheld work, later I began using it under the 1st table. Because I was still using it for handheld work I didn't want to remove the springs, and frankly it is a PITA to remove it from the table plate, install and center the base then put it back in the table again. I eventually bought a motor and lift specifically for the table.
My suggestion is put up with the changes till you can afford to purchase another dedicated router for the table. I don't know the spec wgt of the old 7539 is but its heavy, the more you use it the more bit changes and set ups, handheld no biggie from the table Oye!
Never bite the hand that looks dirty!
The more you know the more you're worth