Thanks, 66 - I've used about all of the hobby fillers over the years, Tamiya is my fave so far. I called Aves on the 800 line, when I related what I would use it for, the lady said their "Fixit Paste" is best for seam filling, etc. One part, water soluble, shelf life 2-3 years.
Her description: Dries rock hard, no shrinkage, sand-able and file-able, thin with water if needed. I ordered a one ounce tube, US $8.00. I'll post results when I've had the chance to use it. What I have disliked about most of the hobby fillers is the shrinkage and age cracking. Hopefully this will work well. Thanks again.
Patrick