If you just enlarge it it won't fly the same as the smaller version! It's a skilled job to make the model just light enough to fly well but just strong enough to withstand any strain placed on it.
There is a 47 inch Great Lakes by Gordon Whitehead in the RCM plan service
https://www.rcmplans.com/index.php?m...ha_filter_id=0
This is a scale version of the Harold Krier Great Lakes Special which was a modifed Great Lakes trainer with radial engine & rounded fuselage The model design was also published in RC ModelWorld Jan 1990 so the plan should also be available from Traplet in England