This paper briefly reviews our earlier study done on estimated errors in various output fit parameters resulting from a specific force-free interplanetary magnetic cloud model <Lepping et al., 1990>, applied to randomly noised-up fields of simulated clouds, and shows that such random noise simulation studies are inadequate. It then proceeds to carry out an error study of the same model output parameters on the basis of more realistic input magnetic field noise sets derived from actual clouds observed in WIND data over the years 1995 to 1998. In this part of the study, 1824 noised-up simulated clouds are produced for use in the same force-free cloud model to study the spread in values for each of 7 model parameters, plus associated quantities, as a function of noise level. Four noise levels are used with RMSs of 0.5, 2.0 (typical level), 3.0, and 4.0 nT per field component of input bias-free fluctuation fields. These are based on manipulation of difference fields from 19 actual magnetic clouds, where a difference field is defined as the vector difference between the observational field and that from the original model fit for each actual cloud. The averages and RMSs of 240 output (model fit) parameter distributions are produced and discussed. The study determines how the model fit parameters, and especially their distributions, vary as a function of various input noise levels and of the resulting least squares $left(chi^{2}right)^{frac{1}{2}}$ values for various exact input parameters, such as the cloud's axial attitude and the closest approach distance of the spacecraft. Practical goals were to better understand the fit program's limitations and to provide a prescription for estimating future errors in specific magnetic cloud (and probably magnetotail flux rope) fittings. The degree of symmetry in the model solution is used along with $left(chi^{2}right)^{frac{1}{2}}$ to judge the quality of the fit.