The V-shaped implant, happened when we moved to Riverside, CA, around 1958, and they tried me out for the MK Monarch program (then mostly around Anaheim- the brand new "Disney Land" no less). I was five years old and already had two encounters with "gray aliens", at school, and one night in our garage. The little gray Emerther aliens (I thought they were 'martians' at the time) came into my room, and floated me out to a craft, hovering over our backyard, and inserted the "triangular thingie" (my term then) up my nose, until it "crunched" and gave me the world's worst nose bleed for a while. My mom called a doctor and also a Dr. George Estabrooks showed up: To hypnotically convince me that these were all just figments of my creative imagination (child prodigy). There are implants in me from about four different factions of spooks and/or aliens in me. Nearly ALL ULTRAs that were used actively at any times, have THREE specific implants (and possibly more, but ALWAYS these three): One at the base of the skull in back, one in the bone under the left ear, and one in the left hand, usually easily visible, but not always, yet seen on x-rays.
I have those same implants too! That is so creepy that the v-shaped one in your hand is associated with Disney Land! I was never there, but my folks used to go every couple of years when I was a kid. My enrolment in the MK Monarch program likely related to that. No doubt it was a really cool place when it first opened! I have a v-shaped scar between my forefinger and thumb on my left hand, and recall getting the one in my toe when I was 5. It hurt and was awful. Although I have one up my nose like you and @Nate, I have no recall of that happening. I suspect it was put there when I was a baby, before my birth family left the island with me in 1976.