[Tigers] Retractable Shoulder Seatbelts in the Tiger

[Would U. Believe]

The one thing that bothers me about driving my Tiger is the lap seat belts
in it. These are mounted to loop bolts through the floor.  I hate these
things; they make me feel really unsafe.  I would really feel better with
some retractable shoulder belts.  Does anyone know the best way to install
these and where to buy the best parts?  Thanks.  M