Most folks with a mid-level metal fab experience and a shop with equipment could make the frame all right. I understand that the 8a difference is only in the boom swing setup and otherwise is identical. I had both tractors at the same time before I sold off the 950 and was considering making the frame to mount the same #8 hoe on either tractor. Got a offer on the 950 I couldn't refuse and sold it. Guess I'd consider the job if I had the ability to purchase a #8 hoe at a reasonable price. The ones I've seen for sale were in the $2500 range in this area. The path I choose was to upgrade to a 970TLB with the #8 hoe and mount as part of the deal and have never regretted it. Good price from the 950 paid for most of the trade. 970 you can shift on the fly, has a 4 cly engine that is smother running, easier operator station to get into and out of. My employer had a Kubota
L35 in the same HP range that I thought had a little more guts in the backhoe boom. More money to purchase though. Lucky to have run a 3 point mounted hoe of the same size for reference and from that experience I can say for sure the strongest setup is the frame mount. Lots of my choice was the chance to make the trade that came along, luck. Torch set, welder, metal cut off saw, the ability to heat and bend steel, not to tough of a job. One thing for sure is that JD made plenty of #8hoes.
Chris