Rockfarmer is your conversion expert over here and more than willing to help. This is an older thread but has seen a fair amount of newer activity over the past year or so. Covers most anything you'd ever need to know about the 1111 series.
http://www.arboristsite.com/community/threads/050-051-075-076-info-thread.169996/page-52
I also have a pretty thorough compilation of old 1111 series hard copy manuals and tech notes digitized into PDF if you decide to jump into the project. These saws probably had more weird design and part number changes than anything Stihl ever produced...even changing part numbers for the same parts just to make it interesting for all the Gold Certified techs of the future.
Clutch worm drive setups for the oil pump(s) are probably the most confusing thing to figure out on the saws when it already
is a saw, let alone when scrounging oil pump parts for a conversion. The good thing about a conversion is you'd be starting from the ground up. You can make sure to get all the correct parts in the first place as long as you're forewarned that there are several variations with very little interchangeability (or forgiveness) among the different parts combinations.
Here's my 051. Came from a guy who just had the oil pump 'fixed' at one of the area Stihl dealers. Couldn't have had more of all the wrong parts if it was done as a training session on how
not to do it. Problem is, the stuff today's techs need to know isn't in MediaCat, PartSmart, eSErvice, of just readily convenient in digital form. Gotta get into the old greasy hard copy manuals and tech notes to have half a chance..., and that in and of itself takes some time. (Ask me how I know.) Let's just say I learned more about the oil pumps on these things than
anybody should ever know!
Bottom line; a conversion is totally feasible if you have the determination and a little experienced assistance. You'll end up with one helluva badass saw worth three times the value of that chop saw..., and a lot more fun to run.
If there's anything I can do to help, be more than happy to assist. Check out Rockfarmer, too. Tell him I sent ya. LOL