Well, here's an update for anyone who cares. I now FINALLY have all the bits and pieces I need to sort this out. From greg's "learn me a bit coin" website, I found an example of everything EXCEPT the coinbase value. What WAS included was everything else, plus the 32 bit double SHA256 hash of coinbase. Tonight I just found out that you can use this URL is you have a coinbasehash, and it will tell you the original coinbase value. [Obviously it cannot hash backwards, but it searches the block chain for the hash, and finds coinbase elsewhere in the block that it came from:
https://blockstream.info/api/tx/<inset coinbase hash here>/hex
for example:
https://blockstream.info/api/tx/18a16d322b235f636ab90e62e79a9f20a0b9c14e8da51e9dc0974f99f82ee444/hexThis gives coinbase=01000000010000000000000000000000000000000000000000000000000000000000000000ffffffff0804233fa04e028b12ffffffff0130490b2a010000004341047eda6bd04fb27cab6e7c28c99b94977f073e912f25d1ff7165d9c95cd9bbe6da7e7ad7f2acb09e0ced91705f7616af53bee51a238b7dc527f2be0aa60469d140ac00000000
Now you can break this apart as follows ... ask ChatGPT for the details:
01000000
010000000000000000000000000000000000000000000000000000000000000000000000
ffffffff
0804233fa04e028b12
ffffffff
01
30490b2a01000000
43
41047eda6bd04fb27cab6e7c28c99b94977f073e912f25d1ff7165d9c95cd9bbe6da7e7ad7f2acb
09e0ced91705f7616af53bee51a238b7dc527f2be0aa60469d140ac
00000000
and then we get coinbase1 = 01000000010000000000000000000000000000000000000000000000000000000000000000fffff
fff0804233fa04e028b12
extranonce1+extranonce2=ffffffff
coinbase2 = 0130490b2a010000004341047eda6bd04fb27cab6e7c28c99b94977f073e912f25d1ff7165d9c95
cd9bbe6da7e7ad7f2acb09e0ced91705f7616af53bee51a238b7dc527f2be0aa60469d140ac0000
0000
An now, FINALLY we have ALL the bits and pieces required to compute the entire block header.
Everything else required is packed into the example blocks and is easy to find on greg's website. The above was the only missing link.
-gt-