Foma is using the same warm tone emulsion on all 'MG Classic' papers (131, 132, 133, 532 and the unfortunately discontinued 542). According to their data sheet, they made some changes to the emulsion starting with lot number 0680, which are relevant for lith processing.
The papers 131, 132 and 133 are using the same warm white paper base, but have different surfaces. I have only been using the 131 and 133 papers (not 132) and the paper base might appear slightly different due to the different surface structures, but it is the same paper. The 532 and 542 papers are completely different with a fibre based, but not baryta coated base.
The only RC papers available from Foma, the fixed gradation 'Fomaspeed' and the variable gradation 'Fomaspeed Variant') are using different neutral tone emulsions. Foma does not manufacture any warm tone RC coated papers.