confuse reading the ATTiny85 Timer1 functionality

I am planning to use the ATTiny Timer 1 for PLL generating a PWM frequency of 100K Hz which I already use the TCCR1 registers. I also wish to use the TCCR1A register for timer OVF interrupt purpose.

May I know is it possible to set TCCR1 registers and TCCR1A register at the same time ?

As far as I can see the Attiny 85 does not have a TCCR1A register, or maybe TCCR1 and TCCR1A are the same thing

The only reference to TCCR1A in my datasheet is in small print in Section 13.3.1

...R