One thing I would do now, that I didn't know about before is either seal the covering seams all in the area where the exhaust oil gets to...OR strip all the covering off and re-do it with a better material like Ultra or MonoKote...

Have you installed the horiz. stab yet? I would remove the fin covering, and sheet both sides of the fin to make it more rigid.
Also, the exhaust oil has soaked in, and the whole top of the aft fuse. and tail is getting oil soaked...[:'(]

Edit: Did you read the part about perhaps using a different elevator pushrod?
You know Barry, right?! I built a Seamonster/Seamaster (ebay ) clone for him last year, and I used a red tube "Goldenrod" and ran it up the leading edge of the fin, over the top of the stab...(the stock S-M wire elev. pushrod binds in the tube, and when it gets rusty, that makes it worse )

In spite of the few "bugs", it's a good airplane...