I'm a little confused here... So you have a gsm?
Hboot 1.58 is a CDMA hboot, and hboot 1.49 is a gsm hboot.
Obviously an RUU is dependent on which model you have which I'm unclear on at the moment, and also, it will make a difference on which hboot you downgrade to.
I'm pretty comfortable with the CDMA model, but am not familiar with all of the gsm information.
Can you post the information on your bootloader screen and also run a fastboot getvar all and copy paste that information as well?
Don't post your imei though... It will be present in the getvar all.