Hi there, first post here, I am a farm equipment guy but a friend (who is a big CAT fanatic) recently saved this Thew shovel from scrap and we are looking for some info on it. The tag with serial number and patents is there but I believe there should have been a model designating tag on the boom which is gone. 

It’s had a CAT diesel swapped into it at some point. If anybody can identify the model and knows what engine it would have had when new , we would love to know. 

And yes that is an RD6 on a 60 foot pole in the background! 

Thanks in advance!