The strut steps on the 100 series cessna wasn't standard until quite late in the product line. It's now standard, but you'd expext that for a hundred and fifty grand. Lots of the earlier models have this retrofitted, or I guess it could have been an option at the time of purchase.
IMO it is one of the best mods available for the aircraft, but one that seems to be recognised about as much in the breach as in the observance.
BTW, I used to dip my fingers in there, but I gave up because that stuff does really nasty things to your skin. Paint stirer sticks are common in the States - especially as Home Depot gives them out for free. We figure on about 5 gals per inch for the 182. Obviously a swag though as this would require rectangular fuel cells, level ground etc, but it's a good starting point.