Very interesting Bob (first off - thanks for the pics!) --- yes, a couple things are very different. What year is your Visa Sonic? The string mute bar base on yours is on the pg, where as mine (would be) on the body below the pg. The ramp on mine was probably done to allow access for fore-aft adjustment of the saddles as compared to the sunken rout on yours that would make that task difficult. (?) Funny thing, in the Burns book it shows a 1963 Vista Sonic (in red/black) that looks like yours (mute bar on pg) and on my post #88, the pic of a VS with the full string-mute bar is also like that, but the VS in the black & white ad is like mine! (mute-bar on body below pg) Flipping through the 2 Burns books I have shows both examples - so this is something for the Burn fb page members to chew on! (I suspect many are British) None of the pics are large/detailed enough to see the ramp and if both details (string-mute bar on body and ramp) were one way, and the bar on the pg/no ramp were another way. I love a good mystery!
And yes, I dig the strange spray-job on the neck - especially with the full-on red and black front & back haloed hs! Nothing basic about that! The bridge thumbscrews with inset mollies is also different than mine - which is two small screw holes. Also noted round-head bolts on the saddles where as mine are flat-heads. I was thinking of stringing it up with the black tape-wound Roto's - what's your opinion of them on that bass?
The best I could figure, based on components and Ampeg's timeline, is that it's probably a '63. Very few were imported, due to import tariffs making the Ampeg/Burns instruments economically unappealing. I think the only time I've seen a photo of an Ampeg-branded Vista Sonic in use was a factory shot of Dennis Kaeger testing an amp. (I hope I'm remembering that correctly.)
Not real thrilled with the tapewounds, but I've learned I'm not real fond of tapewounds in general. I tried a set of La Bella Copper Whites on my Squier VM Fretless and while they felt okay, the sound was underwhelming and the output was much lower than a set of non-tapes. I think I've got a set of DR Low Riders on that bass now, only because I had the set around and decided to try them on there. I'm tempted to see how the Vista Sonic would sound with a basic set of rounds; might they bring out more pleasing characteristics? Tapes in a way sound like throwing a thick blanket over the amp. My take, anyway, I know others love them.
Let me know if there are other details you want to see.