Tibet - 1 sho - detailed identification will be appreciated [solved]

Could you help me to describe precisely my three 1 sho coins from Tibet:

https://en.numista.com/catalogue/pieces22194.html




I dont know their years, KM# numbers (#21, #21b, #21.1a, #21.1b or #21.2?)
Thanks in advance,
Radek

These coins are not easy.
Many variations.
Perhaps an expert can do more.
http://www.zeno.ru/search.php?searchid=266017

Interesting, and not so complicated once you understand the calendar



1 Sho (1/10 Srang - w/o dot on angles on the other face)
Y# 21.1
Face: ཞོ·གད (zho.ga.da) inside circle and dotted circle
légend: Ɛ-o-3 ༨༠ (cy) Ɛ-o-3 ཉ (cle) Ɛ-o-3 ༡༥ or ༡ ༦ (15 or 16) Ɛ-o-3 ལོ (year) Ɛ-o-3 ༥ ༢ - ༦༠, ༡ or ༢ (52-60 or 1-2)
Weight: 3,95-7,13gr.
Mintage:
15-52 (1918): inconnu - ● - 15-53 (1919): inconnu
15-54 (1920): inconnu - ● - 15-55 (1921): inconnu
15-56 (1922): inconnu - ● - 15-57 (1923): inconnu
15-58 (1924): inconnu - ● - 15-59 (1925): inconnu
15-60 (1926): inconnu - ● - 16-1 (1927): inconnu
16-2 (1928): inconnu




1 Sho (1/10 Srang) - with dot on angles on the other face
Y# 21.1a
Face: ཞོ·གད (zho.ga.da) inside circle and dotted circle
légend: Ɛ-o-3 ༨༠ (cy) Ɛ-o-3 ཉ (cle) Ɛ-o-3 ༡༥ or ༡ ༦ (15 or 16) Ɛ-o-3 ལོ (year) Ɛ-o-3 ༥ ༢ - ༦༠, ༡ or ༢ (52-60 or 1-2)
Weight: 3,95-7,13gr.
Mintage:
15-52 (1918): inconnu
15-53/52 (1919): inconnu
15-53 (1919): inconnu
15-54 (1920): inconnu - ● - 15-55 (1921): inconnu
15-56 (1922): inconnu - ● - 15-57 (1923): inconnu
15-58 (1924): inconnu - ● - 15-59 (1925): inconnu
15-60 (1926): inconnu - ● - 16-1 (1927): inconnu
16-2 (1928)w/retrograde error: inconnu
16-2 (1928): inconnu


dots on arabesques: Ɛ-ȯ-3
Y# 21.2

1 Sho (1/10 Srang (1/10 Srang - with dot)
légend: Ɛ-ȯ-3 ༨༠ (cy) Ɛ-ȯ-3 ཉ (cle) Ɛ-ȯ-3 ༡༥ ou ༡ ༦ (15 or 16) Ɛ-ȯ-3 ལོ (year) Ɛ-ȯ-3 ༥ ༤ - ༦༠, ༡ ou ༢ (54-60 or 1-2)
Weight: 3,01-7,27gr.
Mintage:
15-54 (1920): inconnu
15-54 (1920) error, lion var. I: inconnu
15-54 (1920) error, lion var. II: inconnu
51-15 (1920) year and 15 transposed: inconnu
51-54 (1920) erreur (15-51): inconnu
15-54 (1920) rétrograde: inconnu
54-15 (1920) year and 15 transposed: inconnu
15-55 (1921): inconnu
15-55 (1921) year and 15 transposed: inconnu
55-15 (1921) year and 15 transposed: inconnu
15-56/5 (1921): inconnu
15-56 (1922): inconnu - ● - 15-57 (1923): inconnu
15-57 (1923) year and 15 transposed: inconnu
15-57 (1923) error, year and 15 transposed: inconnu
15-58 (1924) year and 15 transposed: inconnu
15-58 (1924): inconnu - ● - 15-59 (1925): inconnu
15-60 (1926): inconnu
15-6 (1926) erreur (60-6): inconnu
16-1/15-60 (1927): inconnu - ● - 16-1 (1927): inconnu
16-1 (1927) dot below syllabele "rab": inconnu
16-2/1 (1928): inconnu - ● - 16-2 (1928): inconnu




Variant: lion's head, size and circles
1 Sho (1/10 Srang - vertical leg)
Y# 21a
Face ཞོ·གད (zho.ga.da) inside circle and dotted circle
légend: Ɛ-o-3 ༨༠ (cy) Ɛ-o-3 ཉ (cle) Ɛ-o-3 ༡༥ or ༡ ༦ (15 or 16) Ɛ-o-3 ལོ (year) Ɛ-o-3 ༥ ༦ - ༦༠, ༡ or ༢ (56-60 or 1-2)
Weight: 3,43-4,73gr.
Mintage:
15-56 (1922)lion var.I: inconnu
15-56 (1922)lion var.II: inconnu
15-57 (1923)lion var.I: inconnu
15-57 (1923)lion var.II: inconnu
57-15 (1923) erreur: inconnu
15-58 (1924)lion var.I: inconnu
15-58 (1924)lion var.II: inconnu
15-59/8 (1925): inconnu
15-60/59 (1926): inconnu
16-1 (1927): inconnu
16-1 (1927)+dot above o: inconnu
16-2/1 (1927/8): inconnu
16-2 (1928)lion var.I: inconnu
16-2 (1928)lion var.II: inconnu

Make your choice

Still no idea which coin corresponds to which KM number

Frenchlover: What are KM numbers for the last two coin types you described? #21, #21b, #21.1b or #21.2?

I dont know yet what is my coin first from left but middle one should be #21.1 and right side is #21.1a
Do you agree guys?

Anybody knows the issue years of them?
Thank you,
Radek

The coins from left to right are as follows
Coin 1 :- BE 15-60 i.e. 1926 KM# Y#21.1a
Coin 2 :- BE 16-2 i.e. 1928 KM# Y#21.1a
Coin 3 :- BE 15-60 i.e. 1926 KM# Y#21.2