...for the longest time, I had two 'spare' vehicles sitting in the yard...both fitted with the Recaro seats...both (later) 1st gens.

Murphy's Law has it that you never need them when you have them...and that you do when you don't. Sorry, I'm all outta spares, now. Those vehicles have (most likely) been reborn, as irons or washing-machines...the wheel of recycled life...

You can always fab. something to your need, or have a shop do it for you. With seat brackets, I'd probably tend to over-fab...since those seats hold you in the vehicle in life-threatening emergency situations....