How is "按揭" a Cantonese loanword of Mortgage from English? I've seen a few claims that 按揭 is a loanword from English.

This article on cnki says:


  【摘要】 &lt;正> 《咬文嚼字》1997年第1期《试说“按揭”》一文说:“‘按揭’源于英语的mortgage。该词的后一半,gage的发音和广州话‘揭’的发音(kit)相近。可以肯定,‘揭’是音译。而‘按’却是意译。广州话的‘按’也有押、抵押的意思。……‘按揭’是一个半意译半音译的外来词。” 


This comment on iask goes a step further to say that it is a transliteration.


  “按揭”是粤语的音译。“按揭”这个音译词要比意译简单,颇有新意和广告效应,并且国际通用,所以就比较盛行。我们传统的民族文化心理在吸收外来词时始终表现出一种倾向,即拒绝纯音译词,而乐于接受意译或部分意译。但是在新的历史条件下,人们的传统观念日益更新,更趋向于接受纯音译词,因此音译词的数量迅速增加。


The ending "-gage" in "mortgage" sounds nothing like ‘揭’ (kit) to me. 按 as "on" seems even less convincing, although it seems like a case could be made for "ngon." 

Maybe something in the sounds is getting lost on me. Any ideas?
Wiktionary [1] claims that among the explanations, none claims that 按 is a transcription for mort-. Seemingly there is a version that the original first character was 摸 /mo2/, which makes more sense, and it was replaced by 按 by meaning.

/mo2kit3/ is a MUCH better match than /on3kit3/, and with what other final could English [gɪdʒ] be approximated, if Cantonese allows only -p, -t, -k outside of nasals? [t̚] and [dʒ] are both approximately dental as opposed to labial or velar, and, as any Korean would confirm, when finally unreleased [tɕ~dʑ] defaults to [t̚], so transcription appears flawless. As soon as English card goes to /kaat1/ [2], the behaviour of [dʒ]should not be surprising.

References:

[1] https://en.wiktionary.org/wiki/%E6%8C%89%E6%8F%AD

[2] https://wenlin.co/wow/Special:Wenlin/QQs%3Fs%3Dkaat1