I am in the same boat and the reply I got from ICOM tech support says you can use the A210 connector and Spruce has these at the time of this post.....
Here is a copy of ICOM reply.
Greetings charlie,
Thank you for contacting Icom America.
You can use P/N 6510030970 in lieu of the original P/N of 6510013850. You can order this part by contacting our Parts Dept at (800)346-0495 Mon-Fri 7am-4pm Pacific.
Click here for information regarding Warranty Registration, Service/Repair Authorization form, Knowledge Base & Technical Support: http://www.icomamerica.com/en/support/default.aspx
Note: Mention of third party products or services is provided for customer convenience and does not imply an endorsement or quality assurance by ICOM America.
Sincerely,
Greg Popovich / KF2M
Technical Support Representative