It was a thing then - many players "goosed" their bass presence by modding their Fender P's & J's with a Gibson EB-0 neck-hugger/mud-bucker. Rick Laid of the Mahavishnu Orchestra also.
I can't find a pic of RL playing his P-bass w/added mud-bucker, but interestingly enough considering current topics here - he also played a Dan Armstrong/Ampeg clear-lucite bass. He used Ampeg SVT's and Acoustic 360's. (...but not at the same time!) The Mahavishnu Orchestra were the cutting-edge of jazz-rock music then. (born of Miles) They only made 4 recordings, the last coming out many years later. (a 'lost' studio version of the 3rd live LP + added songs by the other three band members) Everyone who followed them then heard about a 4th LP but due to internal issues - it was not released until decades later after someone 'found' the tapes in the Columbia vaults collecting dust. It's quite remarkable as the live performance of "Between Nothingness and Eternity" (last of 3 Lp's released in the '70s) is exact - they were scary tight players playing crazy sophisticated music.
There has never been a band to come close to equalling them to this day.
View attachment 4928466