Scale Aircraft Conversions specializes in white metal replacement parts. Its line of replacement landing gear has been expanded to include a set for the Tamiya 1/48 Spitfire Mk.I/Vb.
The set includes 3 parts, two landing gear struts and tail wheel, finely molded in white metal. These parts are drop-in replacements for the plastic parts.
You can see from the pictures the parts are very cleanly molded and formed. They include the “double slot” in the struts where the plastic landing gear cover is attached, so replacement should be quick and painless.
Typically I tend to think of replacing a plastic landing gear by a white metal one when the model is large and heavy. For most single engine 1/48 scale models, weight is not an issue.