Probable remote code for my new el-cheapo universal remote

I've got an old first-generation Sony Tivo.

While my remote was AWOL, I bought a cheap universal remote to use. But, the two Tivo codes listed with the remote did not work on my Tivo.

The remote brand appears to be Vextra.

Is there anywhere that I can find the appropriate remote code (or at least get a reasonable guess for same)?