" I don’t think of Brit Invasion pop as being influenced by R&B and funk during the mid-60’s, but I am open to being shown otherwise…"
You’re serious? Well, let me show you otherwise then…
Even the late period Beatles were massively influenced by R&B and soul. E.g. “Got To Get You Into My Life” is a Motown homage (the Beatles were big Motown fans), “Don’t Let Me Down” is a soul tune, “Oh, Darling!” a 50s R&B tribute, etc.
And in the early days of the British Invasion the R&B flavor was even more pronounced. Indeed, the invaders were arguably more influenced by R&B than by the blues, or for that matter, by white rockers like Elvis or black ones like Chuck Berry.
Let’s look at the debut albums of a few Brit groups of the day and see how many songs are covers of American R&B tunes. Original artists in parenthesis…
-The Beatles. “Anna” (orig. Arthur Alexander), “Chains” (Cookies), “Boys” (Shirelles), “Baby, It’s You” (Shirelles), “Twist and Shout” (Isley Brothers).
-The Rolling Stones. “Route 66” (Nat Cole), “You Can Make It If You Try” (Gene Allison), “Can I Get A Witness” (Marvin Gaye), “Walking the Dog” (Rufus Thomas). Plus covers of blues tunes “Honest I Do” (Jimmy Reed) and “I’m a King Bee” (Slim Harpo) and black rock tunes “Mona” (Bo Diddley) and “Oh Carol” (Chuck Berry).
-The Who. “I Don’t Mind” and “Please Please Please” (Both James Brown)
-Herman’s Hermits. “I’m Into Something Good” (Earl-Jean), “Sea Cruise” (Frankie Ford), “Mother-In-Law” (Ernie K. Doe)
-Moody Blues. “I Go Crazy” (James Brown), “Go Now” (Bessie Banks), “It’s Easy Child” (Freddie King), “Can’t Nobody Love You” (Solomon Burke), “I Don’t Wanna Go On Without You” (Drifters), plus the blues tune “Bye Bye Bird” (Sonny Boy Williamson).
-Zombies. “You’ve Really Got a Hold on Me” (Miracles) and “Can’t Nobody Love You” (Solomon Burke) plus Muddy Water’s blues tune, “I Got My Mojo Working”
-Searchers (actually their 2nd album). “Sweets for My Sweet” (Drifters), “Love Potion Number 9” (Coasters), “Stand By Me” (Ben E. King), “Money” (Barrett Strong), “Twist and Shout” (Isley Brothers)
Only the Kinks avoided any R&B covers as such, sticking to either blues, Bo Diddley, or Chuck Berry.