the replica is arranges such that model_components results as follows
[{'name':'alpha2-1','value':0.98,'flag','~','limits':(0.1,1.9)},
{'name':'alpha3-4','value':1.01,'flag','~','limits':(0.1,1.9)}
{'name':'mg','pars': [{'name':'A231','value':0.25,'flag':'~','function':'','plot':None,'rlocal':True,'glocal':False},
{'name':'B231','value':20.0,'flag':'~','function':'','plot':None,'rlocal':True,'glocal':False},
{'name':'φ231','value':0.0,'flag':'~','function':'','plot':None,'rlocal':True,'glocal':False},
{'name':'σ231','value':0.2,'flag':'~','function':'','plot':None,'rlocal':True,'glocal':False}]},
{'name':'A232','value':0.0,'flag':'=','function':'P[3]','plot':None,'rlocal':True,'glocal':False},
{'name':'B232','value':0.0,'flag':'!','function':'','plot':None,'rlocal':True,'glocal':False},
{'name':'φ232','value':0.0,'flag':'!','function':'','plot':None,'rlocal':True,'glocal':False},
{'name':'σ232','value':0.0,'flag':'=','function':'P[6]','plot':None,'rlocal':True,'glocal':False}]