The earliest Uebelacker label I have found look like a seal with the text "Ü Keramik". Since the  Ü and the text "Keramik" is in two circles it looks like a snowman or the Star wars robot BB-8. The year Uebelacker started to use this label is not known. It can be found on typical 40s - early 50s ceramics. Since the label can be found on exported ceramics (found in Sweden) I guess it was used in the period after the war. 

The label comes in four colours, silver & black, gold & black, gold & red, and gold & black & red.

Ü
Keramik
1945 - 1949?

A label formed as a crest with the letter Ü was used in the early 50s.  This label is documented on ceramics from 1953 (form 369 30  Horst  Makus) and on red ceramics that probably is one of the selenium red glase that was introduced 1954.

The label comes only in one colour, silver&black, but two versions have been found, one with small hooks in the curvy contour and one without small hooks. The label without the small hooks are the most common of these two. 

In Horst Makus book "Keramik der 50er Jahre" there are pictures from a catalog from 1955 with the next generation of label so this label must have been used until 1954.

Ü
Keramik
1950 - 1954?

The next generation of label is an oval silver label with the Ü  and the text "Keramik". It is dokumented in a catalog from 1955 (in Horst Makus book "Keramik der 50er Jahre") and in a catalog from March 1957 (se this web site).

The label is in silver& black and comes in two versions. One has a circle in the first "K" and one label lack this small circle. It is the version with the circle that is used in the catalogs. The same label is also common as an ink mark under the base. The label that lack the small circle in "K" comes in two colours, silver & black and gold & black. The label in gold & black is very rare.

Ü
Keramik
1955 - 1959?

The oval label was followed by a similar label with a slightly triangular shape.  The text remains the same, "Ü Keramik". The label comes in two colours, silver & black and gold & black. The label also probably comes in two generations with a small change in the font. The first genaration has a large last "k" in "Keramik".  The label can be found on vase 456 which is from 1960 ackording to Horst Makus. The label also comes with decors that are typical for the early 60s. The next generation of label is found on a vase marked with the year 1964. I therefore date this label to ca 1960-1963.

Ü
Keramik
1960 - 1963?

The next generation of label is almost the same as the previous but the last "k" in "Keramik" is smaller. The label also comes in two colours, silver & black and gold & black. The label is found on a vase marked with the year 1964. It is also common on ceramics with moulded patterns that became popular in the end of the 60s. It is therefore reasonable to date this label to ca 1964-1969.
 

Ü
Keramik
1964 - 1969?

The last two labels Uebelacker used are both circular labels in silver & red.  The firs generation of these labels has the text  "Ü * Uebelacker * Keramik".  It is found on ceramics with typical fat lava decors which were typical for the early 70s.

Ü
UEBELACKER
* KERAMIK *
Silver&Red
1970 - 1974?

The last label Uebelacker used are very similar to the previous one but has an extra text "MADE IN W.-GERMANY.  A vase with a very special decor (fat lava style with a robot like form) was sold on E-bay. This vase was also marked with the year 1978. That particular decor is only known with this label . It is not known how many years this last label was used. It can be found on ceramics with typical 80s decors so it was probably used until the early 80s at least. 

Ü
UEBELACKER
* KERAMIK *
MADE IN W. GERMANY
Silver&Red
1975 - 1989?