There are good reproduction shuttles and bobbins available on Ebay as well as NOS sometimes and used but good sometimes. Vintagesingerparts.com also has loads of parts available for them.
I have a 1912 Singer 27. Makes wonderful stitches. Straight stitch only and no reverse. Wish it were still in the treadle table it originally shipped with. It was electrified sometime in the '40's near as I can figure from the motor and wiring and is now in a portable case.
Without knowing the serial number, you won't do well at all figuring when it was made. If it had the mounting boss for the electric motor on the upright, under the hand wheel, it was 1901 or later. Fiddle base ended, I believe, somewhere around 1890. The model 27 started in 1889 and was produced to 1941. The 128K was the latest vibrating shuttle machine produced 1912 until 1962.