G'day Ben, It makes ya wanna cry doesnt it. As an MF mechanic I have worked on a lot of 135's, in Oz a new 135 was $A 3000 back in 1970 . I guess the price of the rebuild kit is OK , about $A 900 .Be careful of rear main seal, 2 types,the rope stuff or a large single seal, the rope is a real pain in the butt to install. I would suggest that you purchase a full rebuild kit and have the crankshaft checked with a micrometer and if necessary reground and new bearings fitted. If you are doing the work yourself have the cylinder head and injectors overhauled by a competent firm . Also do not forget to replace the waterpump and have the radiator checked by a competent repairer, don't take shortcuts as it could prove costly later, if you can get an engine repair manual on the Perkins AD3 152 engine so much the better, take your time, don't rush and happy rebuilding . Kerry in OZ.