Since the original window sash, and not the jamb, were replaced with a window replacement insert, to keep the look the same, you need to do some fabricating.
All this is dependent upon if you can find an exact replacement unit to match the one installed in 2007. The chance of that.... maybe. Window manufactures make changes to their product over time. Your window is possibly not in production anymore, but the next generation of window that carries the same size and some the details is what would now be available. Again, this is only a possibility.
What you will need to buy in addition, and this will be much, much more unlikely, is the wood window unit that matches the original one to the house when it was built in 1991. If you do, you would still need to throw away the operable sashes of that unit and install just the jamb. A big expense just to throw away a major part of it.
If it were me, I would get the materials to make a new wood jamb to match the one installed in 1991.
Construction details for wood window jambs are really quite basic construction. A tablesaw and miter box is all that is needed for tools along with drill and screwgun.
Priming everything before assembly would be essential.
The brick mold on the outside of the window may be the only other part difficult to match exactly. All are basically the same size, but there are minor detailing differences from one supplier to the next. Some folks don't worry over this too much since the differences are so small.
