Unusual Airplane/Overprint

I came across this stamp has anybody seen this yet?

Yep, Bulgarian Airmail, overprinted on a King Boris III definitive.

This was issued in 1945, over a year after the death of King Boris III.
Minimum cat value. One of a set of 6, the 4 higher values are imperf.

Tina....Go to Bulgaria, after the main list[A numbers] you will come to the Semi-Postal section [B numbers] and then the [C numbers] airmail section. The same rule applies to all countries. Then go down that list until you see your stamp. You may see the same overprint on a different-coloured stamp, and you may have to look in more detail at the text and list itself if the picture is not on view.
In this case you will see it's Scott#.....well, you tell me !

Hope this helps.
And did you read my long email from yesterday ??

Londonbus1......Finger tappin'

yes Londonbus I did read your email,but one problem I quit drinking almost 6 years ago in oct 21 will be 6 years since i've had a drink of alcohol,I happened to have liked it to much,so it best I quit or die alot sooner than I should so I chose to live alittle longeri am headed to my scotts now to look it up

ok I found the stamp I dont know what Nos. means though HELP

C 32 means its the 32 nd airmail stamp issued by Bulgaria

Nos= Numbers