At one time my father had soprano, alto, and tenor new-baroque recorders, all in matching pear wood finishes. I remember the soprano taking missing from my dorm when I was a freshman. The alto and tenor were still in his drawer when he passed away. I should have gotten both of them. I took the alto and later realized the tenor had suspiciously taken leave. My mother and siblings knew nothing.
I became interested in replacing the soprano and tenor. I could only vaguely remember the markings on the soprano, but I am about 90% sure it was an A. Heinrich. The tenor, I never handled enough to know much about it. I remembered it having a single key on the foot joint. Starting with the Heidelberg mark on the alto, I started looking for a matching tenor. I became certain that Heidelberg was not a maker, but rather a stencil of the Schreiber (Sonata) recorders. I picked up a wandering stray needing corks to compare and was surprised to find that the tenon/socket corks were reversed. The Heidelberg had the corks in the sockets, the Sonata had the corks on the tenons.

Otherwise, they looked almost identical (see photos). Later I purchased an Alpine (brand stencil by Roessler) tenor and the seller tossed in a Sonata alto with what he thought was a mismatched foot joint that needed new corks, but all the parts were 100% Schreiber/Sonata to my eye. Best deal I've ever gotten on recorders. No one else bid and I got the pair for $16 + shipping.

The Alpine is really nice and has some unique tone hole placement. The tossed in mismatched Sonata had tenons and sockets like the Heidelberg. So Schreiber/Sonata altos were made both ways at different time but look quite the same otherwise. In the photo, Dad's Heidelberg is the first one on the left. I have since given the two Sonatas away. One went to a drummer that I am trying to turn into a musician.

The other one went to a clarinet seller who was facing dental issues that caused him to abandon clarinet. I encouraged him to take up recorder because of the relaxed embouchure used. Recorders do not place great physical demands on a player usually.
I really like the tone of Dad's Heidelberg. I know it wasn't particularly expensive, but the pear wood Sonata recorders have a very dependable slightly reedy tone and generally project very well, even the tenor ones. The marks can be "Sonata" (earliest) Schreiber/Sonata (mid) or just Schreiber (late). I picked up a Schrieber tenor more recently for a reasonable price that is in pristine condition. I really like the sound of these even in the higher register. The tenor is a very versatile player.