Currency symbols in plain text email

I was wondering if anyone can recommend the best way to show currency symbols in plain text email?

For example, I'm thinking of using the following:

GBP 49.50 rather than £49.50

USD 74.99 rather than $74.99

An email campaign I'm working on has an international audience - and I'm thinking that spelling out currency in letters will ensure consistent rendering across devices.

Thanks in advance for any tips.

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