"meph replacements" that smell like cathinones and are avail in european market (in anticipation of ban on meph specifically, or in response to chinese ban on meph) are usually mixtures of other cathinones (often ones that very little is known about), optionally with added cuts or other crap. The ones that don't smell like cathinones are generally even sketchier stuff.
Ones i've heard of being sold as meph replacements in europe
4-ethyl-methcathinone
3,4-dimethyl-methcathinone
4-methyl-ethcathinone
4-methyl-n,n-dimethylcathinone
4-methoxy-methcanthinone (methedrone, bk-PMMA, really bad news)
As well as mixtures of other well known cathinones (methylone, butylone, n-methyl-butylone, 3/4-FMC, cut MDPV, etcetera).
Most of the meph replacements witches brews of cathinones that have not been widely tested (DMMC+3-FMC+MDPV was being pushed by one vendor a while ago)... Sketchy stuff. Pity the market for cathinones has done downhill that badly.
Could be any of those, plus cuts, non-cathinone stimulants, and god knows what all else. I'd trash it.