I just bought one of these after wanting one for decades! Mine is dated 1943. I’ll post some pictures as soon as I can.

Here's what I found: 1. From: https://www.alamy.com/a-jubilee-cross-for-officers-and-ncos-of-the-royal-and-imperial-hungarian-infantry-regiment-no-62-ludwig-iii-king-of-bavaria-struck-cross-made-of-black-stained-iron-the-reverse-with-jubilee-numerals-1868-1918-width-40-mm-weight-193-g-one-of-the-rarest-bavarian-awards-hitherto-unresearched-medal-decoration-medals-decorations-badge-of-honour-badge-of-honor-badges-of-honour-badges-of-honor-historic-historical-19th-century-additional-rights-clearance-info-not-available-image247877705.html ~Jubilee Cross for officers and NCOs of the Royal and Imperial (Hungarian) Infantry Regiment No. 62 "Ludwig III King of Bavaria", Struck cross made of black-stained iron, the reverse with jubilee numerals "1868 - 1918". Width 40 mm. Weight 19.3 g. One of the rarest Bavarian awards, hitherto unresearched.  2. From: https://devneu.ratisbons.com/61st-contemporary-history-auction/medal-bar-to-a-member-of-both-bavarian-chambers.html details:  Medal Bar to a member of both Bavarian chambers Description: Bavaria, Medal Bar consisting of Ludwig Cross in Silver for the members of both Bavarian chambers for the 100th anniversary of the signing of the Bavarian constitution, 1918, (A total of 250 were coined by the Bavarian mint) together with Bavarian King Ludwig Cross, and Prussian War Auxiliary Cross in zinc. Needle of bar is missing.   Sorry...  Apparently I wasn't "fast enough", so I'll do this again.  Tedious.  Thanks again, "A.I.".  By the way, I am actually answering my own question... [Why did I bother to ask?]   Image 1: https://www.alamy.com/a-jubilee-cross-for-officers-and-ncos-of-the-royal-and-imperial-hungarian-infantry-regiment-no-62-ludwig-iii-king-of-bavaria-struck-cross-made-of-black-stained-iron-the-reverse-with-jubilee-numerals-1868-1918-width-40-mm-weight-193-g-one-of-the-rarest-bavarian-awards-hitherto-unresearched-medal-decoration-medals-decorations-badge-of-honour-badge-of-honor-badges-of-honour-badges-of-honor-historic-historical-19th-century-additional-rights-clearance-info-not-available-image247877705.html ~Jubilee Cross for officers and NCOs of the Royal and Imperial (Hungarian) Infantry Regiment No. 62 "Ludwig III King of Bavaria", Struck cross made of black-stained iron, the reverse with jubilee numerals "1868 - 1918". Width 40 mm. Weight 19.3 g. One of the rarest Bavarian awards, hitherto unresearched.  Images 2 - 5: https://www.emedals.com/collections/europe-germany-german-states-bavaria/products/bavaria-kingdom-a-memorial-cross-for-the-centenary-of-the-constitution-g41661?variant=46126611038485 Bavaria, Kingdom. A Memorial Cross For The Centenary Of The Constitution. Images 5 & 6:  Muster roll for the Royal and Imperial (Hungarian) Infantry Regiment No. 62 "Ludwig III King of Bavaria". Image 7: https://devneu.ratisbons.com/61st-contemporary-history-auction/medal-bar-to-a-member-of-both-bavarian-chambers.html Medal Bar to a member of both Bavarian chambers. Description: Bavaria, Medal Bar consisting of Ludwig Cross in Silver for the members of both Bavarian chambers for the 100th anniversary of the signing of the Bavarian constitution, 1918, (A total of 250 were coined by the Bavarian mint) together with Bavarian King Ludwig Cross, and Prussian War Auxiliary Cross in zinc. Needle of bar is missing. The medal bar is accompanied by a matching and beautiful little miniature chain with 15 mm reductions. The miniature Ludwig Cross in Silver for the members of both Bavarian chambers is a silvered King Ludwig Cross, probably due to the original miniature cross was not obtainable due to its extreme rarity. Image 8:  King Ludwig III of Bavaria. Image 9: Kingdom of Bavaria within Germany.     Mea culpa for all my errors and messy posts.  This got way too tedious.

Nice... I see the second cord from the bottom is a '57er cord.  No swastika on the Hindenburg cross or the War Merit cross.      

What is the significance of the different dates?  

They are there although gradually degrading.   If you want to find out more you start here:-   https://en.wikipedia.org/wiki/Maunsell_Forts   I did a Google search, the results page will show you lots more information.   https://www.google.com/search?q=maunsell+sea+forts&rlz=1C1CHBF_en-GBGB826GB826&oq=maunsell+sea+forts&gs_lcrp=EgZjaHJvbWUyBggAEEUYOdIBCDgzODVqMGo3qAIAsAIA&sourceid=chrome&ie=UTF-8   I saw them in the 1960's when I was taken on a boat trip by my parents.      

From "antique-photos.com".  No longer accessible.  

Anyone know the difference between these crosses?  

Mea culpa for duplicating the image in Post #1.  Sorry for my redundancy.

From "antique-photos.com"...  No longer accessible.   1. Brunswick. 2. Lippe-Detmold. 3. Oldenburg. 4. Bavaria.  

https://images.app.goo.gl/6yKrxnZa5wf5sXyj7   https://images.app.goo.gl/hLJ9gynDz4gna7v18