Irregular variables of type Lb - Energy distributions and stellar parameters

AGE variables of types Lb, SRa, SRb, and Mira are studied by fitting combin ations of blackbodies to visual, near infrared and IRAS data. This paper su pplements an earlier work dealing with a smaller sample of SRa and SRb vari ables. The fitted parameters T*, T-d and R-d/R* are related to physically m eaningful quantities. Also, quantities derived from the fits like the ratio of the luminosities of the two fitted blackbodies are confronted with inde pendent mass-loss estimators. For the O-rich Lb variables all of the 'blue' objects can be reasonably wel l approximated by only one blackbody whereas the 'red' ones need two. Among the 'blue' objects a significant fraction seem to be not on the AGE at all but a kind of 'RGB pollution'. The T* values, reflecting mainly offseted ( -500 K) effective temperatures for objects with small to moderate mass-loss , are significantly higher in the 'blue' cases. Carbon-rich objects differ significantly from the O-rich ones in their fit parameters. Sometimes 'unphysically' low Tx are found - a result of circums tellar reddening in the high mass-loss cases. Furthermore lower values of T d, accompanied by normal T*s and large shell radii are common and can be re lated to the phenomenon of detached shells. S-stars populate a similar regi on to the optically thin carbon stars in their fit properties.