I think -m 2611 or -m 2612 could help here, but you need to append $salt_1 to the password manually, i.e. you construct the password by combining the password and $salt_1 with either rules or fixed strings in masks etc
I think length 28 salt shouldn't be the problem, neither for 2611, nor for 2612 .
Another problem is that md5(md5 ()) is sometimes misleading.... there are at least 2 variants... the md5 hash could be used in binary form or converted to hex e.g. md5_hex (md5_hex (....)) or md5_hex (md5_bin (...)) ... they of course give very different results and therefore it's always good to get the algorithm right and be very specific about the details of how the hashes are generated
I think length 28 salt shouldn't be the problem, neither for 2611, nor for 2612 .
Another problem is that md5(md5 ()) is sometimes misleading.... there are at least 2 variants... the md5 hash could be used in binary form or converted to hex e.g. md5_hex (md5_hex (....)) or md5_hex (md5_bin (...)) ... they of course give very different results and therefore it's always good to get the algorithm right and be very specific about the details of how the hashes are generated