Bantams

The Bantams were one of Premier's mainstays until at least 1965 when their popularity started to wain but they still accounted for probably half of their total output, and are among the easiest ones to find. They have 13 1/2" wide bodies and were offered in two depths. They were offered in several styles and with one or two pickups.

Bantam Deluxe

Top of the line was the Bantam Deluxe. These had blocks and binding fingerboard inlays, a torch headstock inlay and extra curly maple. These are quite rare, and I only have 3 in my database. The sunburst have a (red?) pearloid pickguard material in the catalogs, but I haven't seen one yet.

This guitar is the earliest serial number I have come across (1022) and it exactly conforms to catalog specs, so I'm going to date it to 1955/1956. It has the Dearmond 2000 (dynasonic) pickups, which didn't last very long - I don't think beyond 1958. The sparkle material on the earlier guitars tends to be more silver and later is more gold.

The headstock is bound and has a simpler torch than later examples:

The serial number (3087) on the below is about 500 below a Premier Special Jr which was first cataloged in 1960, so it is probably 1959/1960:

The main change is the pickups to dearmond 210s, the addition of a compass to torch inlay, the lack of headstock binding and the single-ply pickguard. I've seen cutaway deluxes that I consider later with the bound pickguard, so I don't know if this was an actual change or if they had just run out when this one was made.

Bantam Special

The special was originally offered in three colours: Gold'n'Blonde (gold back and sides with a natural top - $200), shaded ($195), Ebony ($210). As a result of this slightly odd pricing structure, the sunburst and blonde models are much more common than the black. The blonde and the black were both cataloged with the sparkle pickguards while the sunburst was supposed to have 3 ply black, but about half the sunburst that I've seen have the sparkle pickguard. 

This is the earliest special I have a serial number for (1349) and it conforms to the 1956 catalog spec. I would guess it's probably from 1956:

This guitar is just 200 serial numbers later (1535) and has the Dearmond 210s and a sparkle pickguard. Assuming that the first guitars with serial numbers were from 1956 then that probably puts the change from 2000s to 210s around 1957. It also means that there were probably no more than about 500 guitars built with the 2000s.

The earliest model I have a serial number for with Fransch pickups is 2727:

This is probably from 1959. I don't have any Bantam serial numbers higher than this with Dearmond pickups, so it is possible that they were all Fransch after 1960 and until around 1963. Most Fransch equipped Bantams have the dogear covers, but some have a plastic surround such as this one (3548):

This one may also have a blender control which was introduced in 1960 (as this is the only one I've seen i can't say for definite that it is original). All the Bantams I have serial numbers for from the mid 3000s have the plastic surround Fransch, but this later guitar (4156):

Has the dogears again. This guitar has a sticker rather than a metal plate for the serial number, so I think it is probably one of the last "All American" Bantams. I believe this is from around 1963 - which is around when Fransch pickups disappeared from Guilds as well - so I think they must've gone out of business around then. As a result, it may be that Premier bought up some leftover stock, or they were using them up after switching to other pickups on the scrolls and went back to the dogear style again for a short period.

I know very little about the later style Bantams. I have no serial numbers for any and I don't know when United stopped making them - possibly only when Bantams stopped being made altogether. The ones I have seen don't look substantially different from the earlier ones aside from the Teisco pickups:

So until I see evidence to the contary I'm going to assume that United kept building them until at least 1970 (United were still going till at least 1975).