Only because the Teletours were advertised as 9US and they fit me like I'd expect 9USs would. It does say 9M on them and the sole looks more like the soles on the SM 9UKs but the boot seems a bit shorter. The SMs only have 8 and 9 printed on them. No letter M.
The SM 8UKs fit with thin socks, the Teleltours with normal socks, and the SM 9UKs with thick or double socks. The Teletours fit me best. Why am I talking about this so much? It's because since you owned these Teletours I use your sizes as a benchmark: I'd probably fit in Crispi Sydpolen EU 42.5 or EU 43, Arkos Greenland 9US although I'm confused that you chose size 10 (EU43 or 280m) for the Baffin Guide Pros
Don't compare the Baffin sizing with those other teleboots. Its another beast entirely. It has a massive plush liner that will probably mat out with time.
Those teletours were also advertized on ebay as 9US but that does not mean anything really as they are old and used. How they fit is what counts. I remember feeling they were slightly too long (didn't like how they bent on the toes I believe) and surely too narrow for me, that was before I purchased a boot stretcher. I'm guessing if I still had them today, I would have stretched them and wore them with very thick socks??? Actually, I wish I had kept them!!!
My guess is the "M" stands for medium not Men (like in 9US). I don'T think there is a men/Women sizing difference in UK (surely not in EU). The wide ski marches should have a "W" instead? I'm sticking with my hypothesis (But i could be wrong, have been many times before!) that those Alicos have UK sizing on them and they are a little small for their size (compared to the ski march for example). Say half a size smaller.
What is your foot length again? Mine are 263mm and probable a EE.
There are no Crispi half sizes, you'd have to choose between a 43 or a 42!