Thanks for your comments.
Gary: I actually took your build as a modelling reference, I'm sorry that your kit wasn't all that good. In my case, the conversion set for the M51 went together with no major issues, the fit was very good and the quality of parts very nice. But I can't say the same of the other conversion made by Greg Buechler for the M50 with IMI 60mm gun, and had a lot of problems both in fitting and quality, so I took them as reference to make everything from scratch, anyway the turned metal barrel is quite good, maybe the only part in the whole kit. I'm now through painting of it so shortly will be finished and posted here.
Cheers