Gearbox issue, Am I in for a rebuild? Options

[TRS63]

Hello all,

I think that my gearbox might need a rebuild but needs confirmation for you all with more experience (IMG:style_emoticons/default/smile.gif)

First, the facts:
-car is my 1974 1,8l, side-shift gearbox, total mileage unknown, no bill about any rebuilt.
-Short shift from Martin Bott in it since ~3000kms, adjustment fine, never had issues.
-all bushings are 2 years/5-6000kms old so quite new
-Gearbox-oil is ~2500kms/8 months old

The issues I encounter:
-since I own it, it NEVER was possible, from 2nd to 1st to downshift while the car is rolling (by impossible I mean impossible without huge grinding).. The PO told me at that time that it is like that with all 914s, never checked and trusted him but unsure now (IMG:style_emoticons/default/unsure.gif) (IMG:style_emoticons/default/unsure.gif) is it true? (IMG:style_emoticons/default/confused24.gif) Since I own it I always put first only with the car not rolling, otherwise stayed in 2nd gear. .if the car is not moving, no issue at all putting first gear (or reverse), no grinding,..

-since the last 2 rides (40kms?), I have grinding issues putting the 2nd gear downshift or highshift. Increased and at the beginning I thought it was when the car was cold, now I don't think so and it happens every ~2 of 3 shiftings (IMG:style_emoticons/default/sad.gif)
3-5th gears are absolutely fine. And as I can select them fine and without any issue, I assume clutch and shifter setting to be fine, do you agree ?

-it seems to be a couple drop under the gearbox, but nothing big. Can't think that a small leakage could cause such issues, what do you think?

My plan:
-put the car on the lift, check every bushings and linkage adjustment
-if I see any issue: bushes, leakage,... I will fix it and try
-if good..Happy me (IMG:style_emoticons/default/cheer.gif)
-if not..gearbox out and rebuild (IMG:style_emoticons/default/sad.gif)

What are your thoughts on my issues?

Thanks

Antoine