Yes they were Poulan part numbers, Poulan built them and supplied parts to Sears, only makes sense that Sears used the same part numbers. They do the same for Refrigerators.
To be honest, your asking me to remember what I did 40 years ago and I was doing things I didn't think too much about at the time. I don't remember taking rim drives off, I think they were all spurs as they were Poulan saws. I know we sold a ton of them and usually never seen them again for service unless they were after bars, chains, sprockets, air filters or such.
I just know when saws came in for bars or chains that had 1/4 on them we usually talked the owners into switching them over to 3/8 LP. They were all happier after doing so, least far as I can remember.
As to a Poulan 25 PS machine? I have learned to not deal in absolutes and with that said, far as I know and remember the answer is no. The P/S machines based on the 25's appear to be only relabeled saws and mostly Sears.
I have many, many years of 25 and S25 IPL's and none that I have show a P/S option for them.
Good luck on your 7-10. I had one here once and lets just say it didn't stick around here long..