nginx try_files from proxy'd app, then nginx - nginx

Question

I'm attempting to have nginx reverse proxy static files from an application if the application is serving them, else serve them itself. Currently, I have this configuration:
upstream app_server {
server unix:/tmp/gunicorn.sock fail_timeout=0;
}
server {
listen 8080;
server_name example.com;
access_log /var/log/nginx.access.log;
error_log /var/log/nginx.error.log;
keepalive_timeout 5;
location /static {
try_files $uri #proxy_to_app;
alias /path/to/__static;
sendfile off;
}
location / {
try_files $uri #proxy_to_app;
}
location #proxy_to_app {
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header Host $http_host;
proxy_redirect off;
proxy_pass http://app_server;
}
}
This works if the files don't exist in /path/to/__static; it sends the request to the application server. However, if the files also exist in /path/to/__static, nginx serves the files itself.
Reversing the try_files line (try_files #proxy_to_app $uri) fails in both cases. If the client requests /static/css/test.css, the application receives a request for /css/test.css, and it never seems to try /path/to/__static even though the application returns a 404.
Updated to include full configuration.

Answer 1

location /static/ {
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header Host $http_host;
proxy_redirect off;
proxy_pass http://app_server;
proxy_intercept_errors on;
error_page 404 =200 /local$uri;
}
location /local/static/ {
internal;
alias /path/to/__static/;
}