Another option could be Earl Gaines "Lovin' Blues - The Starday King Years 1967-1973" (Westside) 1999 .... still available for little money via the "secondary market" ....
Manny Oquendo Y Su Conjunto Libre "Ritmo Sonido Estilo" (Montuno Records) 1983 .... terrific album .... begging for a proper reissue (incl. the original Cover Art) revisited ....
You should also look for Geater Davis .... the Westside compi "Sadder Shades Of Blue" (collecting his 60''/early 70's sides for Seventy 7, Luna and Ace comes highly recommended ....
I'm in general not so fond of Blues/Soul Crossover (do prefer either/or) .... btw another exception to my rule is Mighty Sam McLain "Give It Up To Love" (Audioquest) 1993 .... big voiced offering ....