I have some late 70's doors and one is missing a threshold insert (the adjustable wood kind), anybody know of where one could by just the "wood strip" that goes in and screws down (there seems to also be a small metal strip that sticks up into the middle of the wood, though you can't see it)?
The brown strip down the middle here:
They have about 4 screws that go down into them?
That looks like an "adjustable height" threshold, whereas the "strip" can be raised and lowered using the large screws seen in your picture. Unfortunately, there are many manufacturers (both foreign and domestic, long gone and still in business) and the parts are not interchangeable even if you managed to find a similar item.
You could try this website, a common U.S. manufacturer. Unfortunately, I think we will be seeing a post not long from now that asks something like "how do I replace this entire threshold?"
I second Jimmy Fix-it's answer. I had the same problem and spent hours furiously trying to figure out what to do about what I assumed was a common problem. For your situation (or others in the future, since this was 2 years ago..) it looks like you could have easily replaced the entire threshold. For cases like mine, where the threshold extends far beyond the door frame for decorative purposes, it's far easier to just replace the wood insert. Cut yourself a piece of the correct dimensions from scrap wood and fasten it down however you please. Saves a lot of frustration trying to find the correct matching replacement part, if you have wood threshold inserts like many homes have. Sanding to round the edges a bit is recommended.
Too late for the original poster, but for others who find this with the same issue - looks like someone has them now:
Home Depot does stock some "adjustable height" thresholds. You might be able to buy one and rip out its insert and re-use. Not clear if it would fit right...
and apparently these things are called "sill caps".
