Almost all Telecaster models have been consistently fitted with metal knobs, devoid of any numbers or markings. Shapes and knurl style slightly changed over the years because Leo Fender procured these metal knobs from large TV/Radio/Phone parts manufacturers, without any particular spec requirement.
These chrome plated dome knobs were machined from brass rod until 1957, when, with the purpose of saving cost, Fender switched to the molded flat top knobs made of the lighter aluminum alloy known as Zamac.
Prototypes, pre-production and early production guitars were fitted with the same tall dome knobs used on lap steel guitars.  They featured a fainter dome as well as a coarser side knurl.  Their style was consistent through the whole year, until the early 1951, when a slightly shorter version with a neater dome was adopted.  However, between 1951 and 1956 different types of dome profile and knurl pattern can be distinguished.

1952 dome knurled knob

1952 dome knurled knob

1960 flat top knurled knob

1968 flat top knurled knob

1977 Telecaster custom knob, Courtesy of Guitar Point

The very first Telecaster Deluxe models made in late 1972 and the Telecaster Custom that were redesigned in 1972 initially featured Stratocaster-style black plastic knobs and then Blackface-Amp-style black plastic knobs, with a 1-10 graduation and a metal cap reading VOL. and TONE.
In late 1977, Telecaster Custom, Deluxe were again fitted with Stratocaster-style black knobs as well as the revamped Thinline model.