I accidently bought a Peruvian sow (Marmite) when I was 22 (I say accidently- I bought the guinea but didn't know she was Peruvian until she grew her fur)
I got her used to washing and combing as a piglet, but kept her fur floor length, more for her comfort really. Though she was a stunning looking beast, jet black, I had no desires to breed or show her.
Hair over the faces doesn't bother them, but I'd keep the fur round the bottom trimmed (thinking of wee/pooh stains and the risk of the dreaded flystrike)
We had Hermione, a long haired sow before the boys. We had to trim her fur or she would get a bit messy and tangled and the fur near her bottom got a bit smelly. We used to put her on the table and trim around where her fur met the table. Had to wrap her in a tea towel to do hr bum and you would have thought we were murdering her from the squeals!! If they are board watch you don 't snip their boy bits!
This could be the most silly question, but is there such a thing as Guinea Pig Grooming? One of our lovely girls is long haired and although we bath her and gently brush her, she is looking a bit scruffy and I wondered whether you ever take Guinea pigs to have a trim! He hair is flopping in front of her face and it quite long althe way around.
Thanks and sorry if this is daft, it's just an idea!