Thanks Giomen. Both Caty & I said they would work and I told aajuno to do as Roger suggested and try it (then see firsthand if works in sd). See Post 62 for what Garmin answered when asked. In part:
I wrote to Garmin support regarding if it is possible to move G2S and DB files on SD card because my Nuvi 3760T main memory is almost full
They replied to me as follows:

Dear .......,

Thank you for contacting Garmin Europe.

I am happy to help. The files which you mention would need to stay on
the device and would not work on a SD card. I would recommend removing
some different files from the device to clear up space on your device.
Please find below information on doing this. ......