RE Donaldson.... I fancied him (not like that!!) a few years back, but haven't seen him rip up trees since, so I guess this is a cheap, last-chance saloon for him in Super League....
RE Jimmy Keinhorst.... There must have been something about him that didn't suit Brian Mac... I think he was one of our most solid players for the last couple of years... Never gave less than 100%...Not a flash player, but never let us down. I wish we had kept him, and reckon he could come back and bite us (as well as others) on the !!

Too true mate but maybe with his drive and enthusiasm he can help some of the youngsters progress.
Like I mentioned before if he was already with us I would be reluctant to let him go and see him well above the likes of Walters, Ormandroyd, Mullalley, JJB, Sutcliffe if he is now a forward and on a par with Ferres unless he gets his finger out and Ablett who has been poor for the last 2 years.
Like you say time will tell.

What is Donaldson’s height and weight?
How does he compare to someone like John Bateman?

You can't compare someone like Donaldson with Bateman as Bateman is a one off. Probably the pound for pound strongest forward i have seen since Ellery Hanley. Yes they are probably similar size but one has freak strength the other doesn't.

I've seen Bateman and Donaldson in the same side and I agree with you. Donaldson has his strengths (defence and work ethic) but Bateman is a freak. He was at my amateur club the year above me and people were saying he'd play for England eventually when he was 14/15. I think our best youth product since Burgess and we have a few of them knocking around (Whitehead, Trueman, Burgess bros.) Unbelievable strength as you say.

Anyway I wish we could have kept Donaldson as I like his work ethic and defense. However I do hope he proves to be an asset to yourselves this season and earns a longer deal. Although I do think you have some very good young players ready for that spot such as Cameron Smith (again he was good for us the other year on loan).

Wiki said something like 5'11'' & 13.5 stone. So really 5'6'' & 8 stone.