I have a machine which fits the description of yours exaction except mine doesn't say "30" Deluxe. Mine just says; Stradivaro Precision "S" Deluxe--Made in Japan.
I bought mine the Summer of 1962, so it is coming up on the 50 yr. anniversary. It has sewn millions and million of miles. I have made most of our 2 girls clothes, many of my clothes, many sets of drapes and curtains, and about 10 years of quilt blocks, and quilts.
It has given wonderful Service and has never given a minutes' problem. Just now it is having some difficulty with not letting me stitch as fast as I sometimes would like; stitches pile up when I sew too fast.
So, I am hoping to come across a website for Stradivaro to ask that question.
I paid $90.00 for it at that time. The salesperson said it was a relative of the Singer Co.. It wouldn't have made any difference at that time. We were so poor we couldn't have afforded anything more expensive, and bought this for $5.00 a week, with a coupon book.
I have and still do love this machine! I sew on it during the day in an extra bedroom where I can see the bushes and flowers, and at night on my Featherweight.
It has served me well,and have loved every minute sewing onit!
Mine is Blac k, and this a Blue is the only difference I can see.