Oh dear, Ive just done the piston re-intall a couple weeks ago without spending out on traditional piston ring compressors I struggled to find 2 that were shallow enough and didnt boost the price of re-installing by another £50 (at least) I eventually went to screwfix and bought very large wide hose clips (they are Huge!) that worked REALLY Well I oiled everything and tightened them just enough on the rings so they moved but not too easily After spending an hour trying to get the rings in I used them and it took about 10 min They come in a pack of 10 I will PM you and can send you 3 out in the post https://www.screwfix.com/p/t-mex-stainless-steel-worm-drive-hose-clips-70-120mm-10-pack/28347