I managed to solve figure out how it is done. I am not attempting to tell you something you might already know, but other readers might learn something.
So here goes:
The first 7 preamble (or sync bits) is used by the transmitter to wake up the receiver so it can sync its data clock with the incoming bits. (On you marks, get set, go). The Sync bits are not part of the data packet. The same for the last 4 bits. It is the transmitter telling the receiver it is done sending and it can go off and do its thing.
That leaves us with 48 data bits. No need for 16 bits of CRC on such a short data packet. So, I reasoned that the data is from 8 to 47 and the CRC 48 to 55.
Also note that having sync bits, the data is serial and being clocked into a serial shift register.
I then remembered working with serial data, PLC and SCADA devices that Checksum8 Modulo 256 was/is very popular due to its low overhead and speed. A quick search and I found this link. http://www.scadacore.com/field-tools/programming-calculators/online-checksum-calculator/
Using the data you provided, I converted bits 8 to 47 to Hex and plugged it into the calculator. Success on all four.
If you have more data, you can run more tests.
For bits 40 to 47, you are back to the drawing board.
My guess it is humidity. Pull the PCB and see if there are any unsoldered pads near the edge. If there are, it might be floating inputs which is a big no-no in electronic design. They should be terminated with either a pull down or pull up resister. This might explain the bit changes in those 8 bits. On the other hand, it might be some other data.
Hope this help