Interesting argument... but wrong.
The failing in your comparison is that the body structure of your Chestnut sparrow is not the same as a California Condor. You're basing your 25 times scaling on Wing span... not body length and breadth, where the bulk of a bird's mass is concentrated.
As I have indicated by frequent statement, the proportions need to be close to identical in the comparisons.
Your Chestnut Sparrow has a wingspan about equal to its body length including tail feathers... that's a 1 to 1 ratio or around a 4.5" wingspan.
The California Condor - like the Teratorn - has a wingspan that is ~3.5 times its body length including tail. The Teratorns and the Condors share similar structure with wing span to body length ratio of about 3.5 to 1.
The short, stubby, flapping wings of the Chestnut sparrow are not in the same proportion to its body length and breadth as the long gliding wings of the Condor and Teratorns to their body length and breadth.
Chestnut Sparrow
Cute little fellow, isn't he?
California Condor
Ugly fellow, isn't he?
Raptor proportions
California Condor is at the top.
The teratorn body is simply a proportionately scaled up version of an eagle or condor... but your Chestnut Sparrow scaled up to equal the wing span of the California Condor, and all other body parts scaled by the same multiplier, would have a body 9.375 feet long and would not be able to fly either... because he WOULD have the weight you calculated.
Let's do it properly and calculate the body mass of your scaled up sparrow using only the body length, which as mentioned above is where the vast majority of the weight of a bird is concentrated.
The body length of an average California Condor including tail feathers is ~45"... so, ~45" divided by ~4.5" (body length of your C. Sparrow) gives us a multiplier of ~10 times... the calculated weight of the ~10 times larger C. Sparrow would be ~103 = ~1,000 x ~13.4g = ~13,400g = ~13.4Kg = ~29.5 Lbs.
Whow... what do you know... while a little heavy for an average Condor (which is probably because the C. Sparrow is considered a "chunky" bird for its size), it's right in the range of California Condor weights reported by the National Geographic's California Condor web page.