Chainsaw Repair

I'm wondering if these molded rubber parts have just all become stiffer with age.  No telling how old the replacement is that I found on ebay - probably been sitting in a repair shops parts inventory for 20 years or more.  I'm wondering how they installed these at the factory.  I'm thinking like a tiny version of a piston ring compressor, but maybe it was just more pliable and could be shoved through by hand.  If I can;t get through any other way, I'm considering cutting the pickup tube suction screen off, then splicing back on afterward with a piece of larger tubing used as a sleeve.  I just don't like kludgy solutions!