Locks and keys, small detail, deep rabbit hole.

Quest for duplicate keys 

Sakura came with a pile of keys, none labelled, and only one for the main hatch.   I sorted out the lot, tagged them all, and decided I should have duplicates for each and a few extras for the main hatch.

 “In 33 years I have never seen that key”.   Thus spake the learned locksmith at Kennedy's locksmith in Willemstadt.  Not surprising and I'm sure he knows his stuff.    I will order blanks and have him cut them on my next visit.  (There's always something that has to wait till next time.)

Here's an enlightening exchange on the alubat FB group.   Thanks Mac!

The conversation continued.  My thanks to Alubat FB group members for providing assurance that this is a common key (and for cheap locks!) in Europe, and particularly to Anne-Marie, who photographed her recently-cut keys, their manufacturer and part number  Silca UL060.   

Which cross-references to JMA U-2D, a part number which seems to exist in North America, however is not commonly available as such.  
https://www.keyblankdepot.com/product_p/jma3355.htm
$7 for the keys, $75 to ship from Texas to Canada!

Bill F later indicated that an Ilco (a brand commonly available in Canada) 997B worked. 

So, following the next cross-reference trail from Ilco 997B, leads to yale 7D, and another online source.  https://www.clksupplies.com/products/997b-yale-key  I have emailed some local suppliers on this SKU.  

Apparently the following are equivalents:

ANIS A21
CANAS UVS2
CEA UN10
CHARLES BIRCH 5851
ERREBI U4PD
JMA U-2D
KEY-LINE UN4PD
KIS U20
LOTUS UV4
ORION UNL4P

Silca: UL060
Silca: ULO60
JMA: U-2D
JMA: U2D
KL: UN4PD
Orion: UNL4P
CEA: UN10
Anis: A21
Lotus: UV4
C Birch Hook: 585

Add (possibly) for North America
Ilco 997B
Yale 7D