Hi and a warm welcome to the forum.
I went to Bilson but left in '73, but until the early 80s was still living at home on Parragate just along from the school. As much as I fondly recall Keith James who only retired in 2014 iirc (aged 78!), I'm sorry to say I cannot remember your father, or indeed any lollipop men or ladies in Cinderford. My own father also died young of cancer, although not as young as yours, so you have my deepest sympathies in this respect. I'm afraid the only member of the Cinderford Drew family that I can recall is Percy Drew who owned the shoe shop next to Jacobs clothes shop, possibly a relative of yours.
I hope to be proven wrong, but I'm not sure you'll get much success on this forum which is usually for much earlier enquiries. I think you'll probably get far better results if you try the "Old Cinderford" Facebook group, which often discusses Bilson school activities from the 70s n 80s. I do hope Admin don't mind me quoting their website address.
https://www.facebook.com/groups/225306364229519/
Hoping this helps, Jeff.