The four filters used are Rosco #398, #4830, #53, #302.
This is a different group from those I mailed out to a few people. Selecting the right filters is sheer drudgery, but drudgery like working a good jigsaw puzzle is. You have to get filters whose total transmissivity is 1/7.6 (.1316), and whose spectral transmissivities add up to give you a good final spectral sensitivity. This required a spreadsheet where I copied the spectral sensitivities of many of the Rosco filters and combined different groups until I found a good grouping. There is a lot of logic involved in doing that, but there are also several different ways to approach it, only one of which finally worked for me.
I think I have enough of the four I selected left for perhaps 3 more meters, if anyone wants them.
I know this has been a confusing thread, since this final effort is at least the 4th version, and all are different in significant ways. It was a learn as you go experience for me. If it helps in figuring this out, this final version starts at Convert Lux meter to PAR meter?