Any seat with contrast stitching is never the 'safest' option. Without contrast stitching it is pretty straightforward to undertake some re-connolising, even with the seats in situ, at very reasonable cost and with good results.
£35k is some fettling. I thought I spent a lot on fettling but I'm just over £30k at the moment and that includes a full body respray, engine compartment oil tank and side plates refurbished in crackle black, complete repair and sticky removal of all controls (by StickyRX in the US), seats and dash re-trim, powder coated cam covers in crackle red, completely refurbished magnesium wheels, replacement door sill plates plus a whole bunch of minor bits and pieces.