Bought, built, and flew a lot of Scientific models, but the first was the Li'l Mercury, powered by the ubiquitous Cub .049B. One of the more interesting was their Stuka, Tee Dee .049. Flew fairly fast on the almost standard 35' Dacron lines, then somebody lent me a set of 42' .008" steel cable. Basically, I never went back to Dacron.
Only Scientific model I still have is one of their sailing ships, the HMS Bounty. Bought it just before getting out of the AF in 1968, started in 1969, finished in 1977. Miss that brand!
I did put a couple mail orders in to AHC. One with no problem, one, which I sent just before rotating stateside from Wheelus AFB, had quite a bit extra. Seems they combined 2 orders, mine and someone else from another squadron there. Gave me a lot of static over the phone, seems they checked their shipment according to weight, mine was correct. I ended up forwarding the extra stuff to the correct recipient. Hope he got it.