Baltimore Foreign Mail Cancel

Apparently this is a Baltimore foreign mail cancel on this #93 - at least based on what I've found from searches of previous sales etc. But can someone confirm that or maybe point me to a source that talks about Baltimore foreign mail? There's lots of information about NY foreign cancels, but I've come up empty on Baltimore.

Hi rlsny
I know of two fairly recent articles that have info on Baltimore Foreign Mail, both in the US Cancellation Club News - https://uscancelclub.org/
Slotted Baltimore Foreign Mail Datestamps Feb 2020 - US Cancellation Club News - Whole Number 312
Color Cancellations on the 1869 Series: Baltimore Foreign Mail - US Cancellation Club News - Whole Number 286
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Don

Be careful in calling something a Baltimore FM cancel when it is on a grilled black jack. 90% of the time it is a NY City red cancel used on local mail.

Interesting. It certainly seems to be a rare and short lived cancel - maybe used for just a month in 1869. Since the 93 is an 1867 stamp this would justify the previous owners "very rare on this stamp" comment though I have a feeling it doesn't quite justify the $850 price he had written on the stamp holder.

ok, warning noted. Comparing to other examples with certs in Siegel power search certainly looks legit. Here's one for example:

I did NOT say that your example was not a Baltimore Foreign Mail cancel and it appears to be. I was saying that low denomination stamps were you used less often on foreign mail and that the 2c Black Jack exists with greater frequency with red "fancy" cancels of New York City. There is one correspondence from Baltimore with red FM cancels that includes a Magnus patriotic cover with Black Jacks and few other stamps used abroad. A spectacular cover.

Thanks Richard. As much as I appreciate having the opportunity to sell stamps like this. It is often daunting to try and get it right in areas like this where I don't have the background. I appreciate the guidance.