Is there a reproduction company that is making the bucket seat bolts or as part of a interior hardware kit?

Which bolts are you referring to? I don't think the ones to fasten the seats to the floor are part of the interior package. They are unusual; they have flanged heads, and an anti-crossthread tips. (the last 1/4" or so is not threaded) Mine had an "M" on them, and are the same as the deck lid hinge bolts. When I did mine, they were not reproduced...I was a couple short so I used the "M" ones on the deck lid, and used a couple of hardware store bolts where they would not be seen.

Close are the door hinge bolts. Also the battery hold-down clamp is close. The door bolts have serrated washers. The repro hold-down clamp has serrations also. I think I got the clamp bolt from Rick's. #EP-14R. Also look on page 104, 6th item. It is the trunk bolt and listed for seats as well.http://www.amkproducts.com/Catalog_PDF/90-108.pdf

Is there a reproduction company that is making the bucket seat bolts or as part of a interior hardware kit?
I think you are referring to what the Fisher Body manual calls "seat adjuster bolts". The answer depends on if you want something functional or something correct. Our sponsor has what you want under part number BSM-516, but these don't look anything like the bolts in my '67. The AMK catalog has kit G-5148 listed for the parts you want. They also have part B-10895 shown on page 104 of this link: http://www.amkproducts.com/Catalog_PDF/90-108.pdf. It is labeled GM Trunk Lid, Seats. This part looks much closer to my originals. When comparing my trunk bolts to my seat bolts, the thickness of the captured toothed washer is greater on the trunk bolt than it is on a seat bolt. If you insist on original GM bolts, they do show up on EBay every now and then.