Are these shocks interchangeable? Rebuild Swinger?

I bought used a 2005 Trek Liquid rear triangle and linkage. I already had a 2004 Trek Liquid and the 2005 rear end was a fairly cheap upgrade due to dropout pivots. Both bikes use a Swinger 3-way SPV shock, but they are different sizes because the linkage changed.

The 2004 shock is 8.25" eye to eye, 2.25" stroke.

The 2005 shock 7.5" eye to eye, 2" stroke.

I built up the 2005 yesterday and was bummed that the 2005 shock is leaking massive air. So I put the 2004 shock on. I had to deflate the shock a bit because it was too long. When I installed and refilled it also leaked air. Now even more bummed. Both shocks hadn't been used for about 5 months so maybe that contributed? I'm going to have the 2005 shock rebuilt. May try to do it myself but not sure I can pull it off.

Anyway, I read on an old thread that the 2004 shock can be used on the 2005 frame even though it is slightly different size. Is this correct? I'm wondering whether to have both rebuilt for spare or just one. Or just to ditch both and get a coil. I've always had problems with these air shocks. thanks for any input.