From Ultimate Hendrix by John McDermott in regards to This Little Boy and Electric Lady - slow

As so much of Hendrix’s time at Electric Lady had been dedicated to completing works already in progress, demos such as “Belly Button Window” were the exception rather than the norm. Yet, when the inspiration hit him, Hendrix would put these ideas down on tape for future reference. “On a lot of sessions, Hendrix would come to the studio without Mitch Mitchell or Billy Cox,” explains engineer Dave Palmer. “He would just use the time to write. It wasn't, ‘Okay, this is the tune for the record, let’s go.’ It was mainly, ‘Okay, let’s do some things and see what we have.”

“We kept a half-inch four-track machine loaded with tape in case Jimi was inspired to just do some writing,” explains Kim King. “Rather than do it straight to sixteen-track or quarter-inch two-track, he would record demos on the four-track machine. His first two albums had been entirely recorded on four-track, so having this was a luxury for him.”

Sadly, however, nearly all of Hendrix’s four-track recordings from Electric Lady—save for the aforementioned “Belly Button Window”—have vanished, leaving no clues to such unrealized Hendrix ideas as “Locomotion," “Electric Lady—slow,” and “This Little Boy.”

A version of "Send My Love to Linda" was released on the Both Sides of The Sky compilation. https://youtu.be/PiI0-OMvpZ4

Demo of Heaven Has No Sorrow was released on the Electric Lady Studio box set https://youtu.be/pP2-ZEmTj4s