Did I find a KLASSEN sibling?

I've been working on my Grandma Loewen's 23andme matches for about a year and a half.  Her second highest match responded to my messages, and we've been in sporadic communication.  She has VERY strong KLASSEN ties, including a KLASSEN brick wall at the same generation we do.

Anyway, I was finally able to get in touch with Grandma's top match (other than Mom and me), and from their response, it was apparent to me that they were likely to be the aunt of Grandma's second highest match, because they gave me the name of the person the profile belonged to, and it was the same name as Grandma's second highest match's grandmother.

I got back in touch with Grandma's second highest match to see if she knew about this person who was likely to be her grandmother.  She confirmed that she tested both her grandparents, and that her aunt has the log-in information for both accounts.  Her aunt is not well right now, and was not very receptive to working with me.

So, I asked the second highest match if she's sharing with her grandmother's account, and if she is, if she could compare Grandma Loewen with her grandmother's DNA and then let me know where they match.  It's likely that her grandmother and my grandmother are 2nd cousins, which means that our grandmothers' grandfathers are likely to be brothers!

I'm actually pretty excited about this because that would mean that I found one of Peter Klassen's siblings.  I have a name for one of his sisters as well, thanks to a picture I saw at Christmas time that one of my great-aunts has.

Updates!

UPDATES:
- December 8 LOEWEN/FRANZ swab #3--Arrived at the lab on January 21.  I haven't ordered the test yet, but when I have enough, it will be the first one that I order.

-  February 8 LOEWEN/FRANZ swabs #6 and #7--Ordered this morning!
-  USPS raised their prices, so FTDNA had to as well.  Round-trip shipping is now $12.95.

No updates:

-  August 31 PETKAU/KLASSEN swab #2--This one is still outstanding, and as far as I know, hasn't made it back to the lab yet.
- December 31 PETKAU/KLASSEN swabs #3 and #4--These two I assume have reached the testers, but I have no further information.
- January 20 LOEWEN/FRANZ swabs #4 and #5--Ordered. I expect the swabs to ship sometime next week