I have a set of L/R 986 seat belts in excellent condition and a set of new 986/987/996/997 seat belt receptacles.
Although not stock for a 914, these belts and buckles can be direct replacements and will fit a 914 without modification. The only thing you will need to add is the chrome belt holder from your original 914 seat belts. The bolt location and mounting pin are the same size and location as an original 914 belt.
Used, the 986 belts generally run $100.00 or so a pair. The buckles retail for $97.25 each.
Asking $100.00 for all plus actual shipping and PayPal fee.
Thanks for looking!