Old Gabriel aftermarket front shock absorber on XK 120


Discovered that my 1954 XK 120 had Gabriel shock absorbers at the front that somewhere in the past replaced the original Newton versions. Now I read in an old topic on this Forum that there were 2 (potential) US replacements for the XK 120: the Monroe 32143 and the Gabriel 82018.
However my Gabriel has the number 18123 on it (see photo) but I cannot find any reference of this number.
Just out of curiosity: is there any US “oldtimer” that has a Gabriel catalog with the 18123 still in it? What was the original application? Or was it a genuine Jaguar XK 120 aftermarket version by Gabriel? Looking at the later “Classic” Gabriel shockers with totally different numbers, these might well be from the Sixties.
For those interested: they still work fine!!

Bob K.