Hi all - this is the reply that I got from Sea&Sea about the correction lens:
Hello Ido,
Thank you for your contact.
About M82 internal correction lens:
Both M77 and M82 internal correction lens have been discontinued. Because our actual supplier has been closed during covid-19 pandemic.
We have a plan to reproduce them but it is not so soon. Let's say in July or August..
We will keep you updated. Once they are ready, we will announce to public.
We are so sorry for your inconvenience.
Best regards,
Kaz Okada
International Sales
Sea & Sea Co., Ltd.
2F,4-8-11 Nagasaki, Toshima-ku, Tokyo 171-0051 Japan
Tel: 81-3-5926-9320
Mob:81-80-3276-7203