Jack,
I see you’re an A&P, so some of my offerings below may be stating the obvious for you. Still, I’ll share observations from my build in hopes of benefit to you and others, assuming no major design or material changes to the seals since I built 6 years ago. Also, I share your concern about damaging the bushings! I believe I did use a piece of hardwood to gently lever the wing spars into alignment a time or two.
It seems to me in that those seals only serve to fill the gaps and prevent airflow in/out, turbulence and drag at the wing roots. They may also reduce cold drafts on your keister! In my opinion they should be firmly and uniformly (but not too tightly) compressed between the wing skin edges and the fuse skins which are unsupported. We’re not trying to seal a pressure vessel here.
So, before using a LOT of force (such as pipe expanders) to align the wing pins, check a couple of things…(ok 5 things ��
1- Make sure it’s not something else interfering with proper alignment and seating of the spars. I had some proud wing spar rivets that would hang up against the fuse skins. Took me a while to find ‘em.
2 - make sure the gaps between the wing skins and fuse sides are uniform all around ie top, bottom, leading and trailing edges. Carefully and gradually trim tight spots further as needed.
3 - be sure the seals are placed exactly according to the KAI procedure. The seals have a beveled edge, so a little bit out of position one way or the other makes a difference in how they fit the gaps.
4 - once other obstacles have been eliminated, consider additional trimming on the inboard edges of wing skins if needed rather than applying excessive force to line up the pins. I had to do two iterations of this on my early kit #121.
5 - I used a Scotch Bright wheel on each spar pin to slightly round and polish the edge line where the tip bevel and pin barrel surface intersect.
Note: when all is said and done, it still sometimes requires wiggling at the wingtips, cajoling, light lube, gentle hammer taps and appeals to the dark forces to get the pins fully seated.
Perhaps our friend DBRuth can shed light on how to make it go more smoothly since he is able to get his bird off a trailer and ready to launch pretty darned quick!
Lastly I suppose some sort of caveat/disclaimer is in order…my build was an early one. Many changes and improvements have been incorporated in the kits, materials, and KAI procedures. If any of the above conflicts with current KAI, follow the kit instructions!
All the Best and Merry Christmas!