A piston assembly for operative connection to an end (110, 112) of an associated flexible sleeve, said piston assembly comprising: an outer shell formed from thin-walled metal material, said outer shell having a longitudinal axis and longitudinally-spaced first and second ends (148, 150), said outer shell including a side wall and an end wall, said side wall extending generally longitudinally between said first and second ends (148, 150) and including a terminal edge disposed along said second end, said outer shell including an inner surface and an outer surface, said inner surface at least partially defining a piston chamber, said outer surface operative to abuttingly engage the associated flexible sleeve, said end wall extending transverse to said side wall along said first end and at least partially defining a first opening along said first end in fluid communication with said piston chamber, said side wall at least partially defining a second opening along said second end; an end plate formed from thin-walled metal material and including a first side, an opposing second side, and an outer peripheral edge, said end plate also including a first approximately planar portion at least partially defining a first plane, a second approximately planar portion at least partially defining a second plane disposed in longitudinally-spaced relation to said first plane, and a third approximately planar portion at least partially defining a third plane disposed in longitudinally-spaced relation to said first plane in a direction opposite said second plane, said end plate received within said second opening of said outer shell such that said outer peripheral edge is disposed along said inner surface of said side wall of said outer shell and positioned relative to said outer shell such that said first plane is disposed along said side wall within said outer shell and said second plane is disposed longitudinally-outwardly of said outer shell with respect to said terminal edge of said side wall; an attachment column extending longitudinally between opposing first and second ends (186, 188) with said first end disposed toward said first end of said outer shell and said second end disposed toward said second end of said outer shell, said second end of said attachment column abuttingly engaging said first side of said end plate of said third approximately planar portion thereof; a first flowed-material joint disposed between and fixedly attaching said end plate and said outer shell to one another such that a fluid-tight seal is formed therebetween; and, a second flowed-material joint disposed between said attachment column and said end plate along said third approximately planar portion thereof and fixedly attaching said attachment column and said end plate to one another such that a fluid-tight seal is formed therebetween. an outer shell formed from thin-walled metal material, said outer shell having a longitudinal axis and longitudinally-spaced first and second ends (148, 150), said outer shell including a side wall and an end wall, said side wall extending generally longitudinally between said first and second ends (148, 150) and including a terminal edge disposed along said second end, said outer shell including an inner surface and an outer surface, said inner surface at least partially defining a piston chamber, said outer surface operative to abuttingly engage the associated flexible sleeve, said end wall extending transverse to said side wall along said first end and at least partially defining a first opening along said first end in fluid communication with said piston chamber, said side wall at least partially defining a second opening along said second end; an end plate formed from thin-walled metal material and including a first side, an opposing second side, and an outer peripheral edge, said end plate also including a first approximately planar portion at least partially defining a first plane, a second approximately planar portion at least partially defining a second plane disposed in longitudinally-spaced relation to said first plane, and a third approximately planar portion at least partially defining a third plane disposed in longitudinally-spaced relation to said first plane in a direction opposite said second plane, said end plate received within said second opening of said outer shell such that said outer peripheral edge is disposed along said inner surface of said side wall of said outer shell and positioned relative to said outer shell such that said first plane is disposed along said side wall within said outer shell and said second plane is disposed longitudinally-outwardly of said outer shell with respect to said terminal edge of said side wall; an attachment column extending longitudinally between opposing first and second ends (186, 188) with said first end disposed toward said first end of said outer shell and said second end disposed toward said second end of said outer shell, said second end of said attachment column abuttingly engaging said first side of said end plate of said third approximately planar portion thereof; a first flowed-material joint disposed between and fixedly attaching said end plate and said outer shell to one another such that a fluid-tight seal is formed therebetween; and, a second flowed-material joint disposed between said attachment column and said end plate along said third approximately planar portion thereof and fixedly attaching said attachment column and said end plate to one another such that a fluid-tight seal is formed therebetween.