Heres a pic of the front of my Husqvarna converted 61cc.
Youll notice the number 48 on the left and the word Mahle on the right.
A LOT of chainsaw manufacturers use Mahle cylinders.
Now on to the numbers.Your number 52 on the left side means the cylinder bore is 52mm.[52mm piston].Using my stroke and math,heres what i came up with.
Bore divided by 2 =26mm
26mmx26mmx3.14[pie]=2122.64x[stroke34mm] =7216.976.
This means this engine is a 72cc actual.If your stroke is 34mm.If its longer your ccs will be a little higher.
The most common engines that i have seen converted are sachs-dolmar.
My Husky case halves bolts come from the rear,not the front like yours.I would say your engine is a sachs based 72cc.