I too have heard good things about North East guinea pig rescue.
Some rescues do have baby guinea pigs. I had a baby at 6 weeks old and one slightly younger from guinea pig rescues but like I say, many rescues do not advertise their babies online as they like to give the older ones a chance.
I have had 7 guinea pigs from various rescues across the Country all from various ages
Eleanor - 6-8 months
Erin 6 weeks
Ena 4 weeks (Although this was an exceptional circumstance why I had her so young, ideally guinea pigs should be 6 weeks plus when they are re homed)
Enoch 6 - 8 months
Emma 12 months
Erika 12 months
Eliza was a pet shop piggy and was 12 weeks when I had her and Connie was around 6 - 8 months. She came from someone who no longer wanted her.
All of my guinea pigs have given me the same amount of love despite their age
I am sorry that you bonded with the babies from the photo's that is only natural. Before I new much about rescues, I enquired about guinea pigs with a local breeder when I was looking for a friend for Eliza after Connie passed. The lady explained that she had no babies available but I could take the mum as 'she was no longer needed'. That upset me no end but I unfortunately had to say no as alarm bells rang and I was offered Eleanor from a rescue. She had had a rough time before she came to me and it filled me with joy that I was able to give her a loving home.
I often think about the piggy the breeder offered me though.