New 1:48th P-38 Sets for the Tamiya kit...

...are now out. There are two sets that cover the landing gear. The first is a 'Full Set', KAZ48017TAM, and it covers the nose and main gear legs, retraction struts for the gears and the doors, along with some enhancements to the nose and main wells. A bonus of this set is that there are four main wheels, covering three different tread patterns, allowing for asymmetrical patterns to be mounted on the model. This was a common practice. 

The retraction pistons are stainless steel cut-to-length tubes that also serve to strengthen the gear. All resin parts are 3D printed. 

The second set is a simplified variation of the above one, covering just the landing gear legs and two, single tread main wheels. The instruction pdfs can be viewed following the link from the product page in the e-store.