I very rarely reuse original liners, muffs, and pistons, as there are at least 6 items that can give trouble and it generally takes just one to cause more grief than it's worth. Here's a good example........I just stripped down a very original and unmolested series "D" engine from an enclosed model. It was running ok, though a bit tired and filling up the primary chain case with oil, due to too much blow by from the rings. After disassembly I found the bores were standard size with early Omega pistons. However the top of the liners had not been sealing in the head recess and the heads had been pulled down to at least 60 Ft Lb's......Thus the heads were sealing via the large broad alloy area. I checked the height of each alloy muff, one was 40 thou under and the other was about 50 thou. There were more issues as well, but I quickly decided to replace the lot, as this fixes many items in one go. Unfortunately I feel the upper and lower guides in the heads are out of alignment due to the excessive amount of torque applied to the hold down studs in an effort to make the heads seal, and this often cracks the heads as each Tower in the head starts to collapse. I learnt the hard way to measure up all the dimensions of old liners/muffs to see if they are still usable, but not many pass the test. It is a risk I am not prepared to take.