Looking at a 25

[Wolverine]

I'm looking at the 25 and have found a discrepancy in the standing headroom. 
I have read it to be 5' 6", 5' 9", and 5' 10".

[doug 26RK]

I don't know the answer to your question, however you can check here https://web.archive.org/web/20151002104221/http://seawardsailboats.home.comcast.net/~seawardsailboats/

It's Scott's seaward site. He had a 25 and a boat full of knowledge. I'm going to be crazy busy and out of the area for the next 3 weeks, at which time I can measure my 26RK, many of the dimensions are similar (its possible the height you have found is variable due to the acorn nuts hanging down into the cabin, I try not wear a hat below so i can see and avoid them). There is also a facebook site which has a lot of activity and likely some 25 owners.

[doug 26RK]

As a follow up, i found this sentence in a practical sailor review of the 25.

Headroom in the cabin is 5′ 6″, but slightly higher in the galley when the hatch is open.

Worth your time to search and find the review.

[sesmith]

In 1996, Hake raised the height of the cabin.  That's probably part of the discrepancy in what you found.  I pretty sure the '96 we had was higher than 5'6" as I could stand up in the center and I'm around 5'8 these days (maybe 5'9") on a good day

[Wolverine]

I'm not on Facebook so I can't get answers there.  Practical Sailor is where I found 5'6" reference.