Re: Happy to disagree :)
We saw what Tom looked like after he made only 1-3 Horcruxes - the wasted look with eyes that only flashed red when he got angry. If there is any description of people with a Horcrux in wizarding literature that's it - not very abnormal. Tom was the first wizard to undergo the transformation we see when he came to interview - I can see Albus interpreting it as the result of Dark magic but he wouldn't connect it directly to a Horcrux because the symptoms were completely novel.