Exactly what I was about to ask...
I've just been looking at the DNA testing kits that are on offer today at £29. I'm not sure how a £9.99 shipping fee is justified but hey-ho. I'll speak to my dad today and see if he fancies doing one with me - it certainly sounds like it could yield some interesting results.
I've actually got more info from my paternal grandmother's side over in Ireland, NORAH/NORA REDDINGTON. I've found a fair amount of documentation relating to the REDDINGTON side of the family, but as my dad said yesterday, "they didn't have TVs in those days" and according to my dad, NORAH was one of 11 children. The biggest issue I'm finding is being able to decipher the handwriting on the BDMs from the Irish sources. The REDDINGTON family lineage looks huge.
I've been using
https://www.freebmd.org.uk/ as well as
https://www.irishgenealogy.ie/ in a bid to try and trace the REDDINGTON line.
I did randomly message one of the MARKERSON grandchildren on Facebook, and whilst the initial response was him confirming he was the cousin of the granddaughter I made contact with a few years back, so is definitely of the lineage connected to GORDON's brother ERNEST, he hasn't responded since. I may take a punt and message one of the other connected MARKERSONs from their connected 'Friends' list as they are all obviously part of the same family.
I did start off on the Ancestry free trial membership but ended up signing up to the Essentials at £10.99 a month. I'm finding though that some of the resources it finds and hints require more expensive subscriptions so am toying with upping that the £13.99 Premium membership for now to see what more that yields.
I'll keep this updated in due course but once again, thank you to all who are helping me research, it's a massive if somewhat interesting journey.