Domed Tropic-22 on a 1016 - Installation Advice

Unsure about exactly which crystal my 1016 would have left the factory with (220XXXX - 1969/70) - and per the conversation in this Instagram thread (HISTORY BE DAMNED) - I am committed to replacing the more modern crystal in mine with ye old domed Tropic-22.

I know Michael Young in Hong Kong sells them, and they are available from many sources, surely also on eBay. Given that sourcing isn't the issue, the only real hurdle is installation.

Based on past requests/experiences, pretty sure I won't convince the RSC service partner here in Dubai to do this for me. So in my shoes, would you feel comfortable in getting a competent but non-certified watchmaker to make this change? Do you know if there is a tension ring or other part required that a less-than-Rolex-certified watchmaker would miss?

In short: How can this go wrong? Other bits of advice welcome.

While replacing a crystal looks as simple as in the tutorial linked below, I would defer to a watchmaker that does this on a daily basis. Further, you would want to get the watch pressure tested. The safest $50 (or around) you can spend.

http://www.watchgeek.com/crystal_installation.htm

An original domed T22 is harder to source than I expected... places I thought had them are in fact only offering aftermarket. I posted a WTB some time ago, but if anyone sees or knows of any floating around please let me know.