FAA ATP CONVERSION to EASA ATPL - TECH QUESTION

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Hi guys and gals,

As much as I researched I cannot find the answer to this question and would appreciate feedback from anyone who knows the answer.

I have completed the required 14 written EASA exams through the UK system.
I have a current FAA ATPL, with over 6000TT.
I did have a JAR medical class 1 back in 2008 when I was flying an Irish reg LR60 out of Russia on an FAA year validation
(the 5 year expiration date was last DEC... oops totally blew that one)

MY QUESTION IS:

Can I go do the EASA initial simcheck in the current typed AC I am flying (G550), prior to renewing my JAR medical, or is it a legal requirement to have the JAR medical current prior to doing the simcheck?

Also can I do the english proficiency, etc after the simcheck also?

Thanks in advance for the feedback!