Don't think the 37xx logo has some connection with the impossibility of using China FW ver 2.50. Could be but I doubt. You can see from other post over the internet that the CHN FW 2.50 works on nuvi 3750 which most probably are using same logo as 3760 and 3790. In the logo.bin I am most interested in the parts between the Part Number and the PNG and header.

Edited...Sorry, I was wrong.