Hi folks, I've just come into possession of an AWA Trender Dimension Sound turntable and GE (Granville) RS8V1 Radiogram. I'm really new to restoring such equipment and am wondering how difficult it would be to find parts

Just about all parts for these items are available.
If not new by scrounging and substitution.
No reason why they cannot be restored to as good as new.
Cabinet bits and trim might be the hardest.
JJ

In case you ever need to replace one, the small AWV made silicon transistors cross to jellybean Philips parts, like so:

AS147 = BC547 (NPN) Also BC107 (metal can), BC147 (lokfit)

AS177 = BC557 (PNP) Also BC177 (metal can), BC177 (lokfit)

In all cases, the last number is a batch spec sort:

7 = 45 volts Vcbo
8 = 35 volts Vcbo
9 = low noise

All these transistors are rated at 100mA Ic and 300mW dissipation.
Sometimes there will be an A, B or C suffix. This refers to the Hfe or current gain ranking, A being the lowest.

BC557s can be used to replace older germanium PNPs, even RF types, usually with no circuit change needed.

I recall doing just this to a UK made radio where all the transistors were dead, possibly due to a reverse polarity incident. That radio acquired amazing sensitivity that, according to its owner, it never had before.