Well, it took longer than I thought, mostly due to issues pertaining to my darkroom situation, but they're worked out now, and although this thread has cooled, I do have some results to offer up to the group. I shot a roll of T-Max 100, developed in D-76, then I shot duplicates of the negatives with my 24.3mp d*****l. I did a minimum of post processing of each shot, just enough to make the photos reasonably presentable.
About my 300mm lens, it's been a while since I've had it out of the bag and I had confused it with my 200mm, which is a late model. The 300mm I have is an earlier model, not sure exactly when it was made. It has a rubberized focusing collar, but the collar's nibs are more finely textured than those on my 200mm. It came with a bayonet-style metal Asahi Pentax front cap.
As for the photos, I shot a group from f/8 to f/16 on one tripod and f/8 to f/11 on the other before I ran out of film. At each aperture setting I took a shot with and without mirror lock up. At f/8 there was a moderate amount of background blur, but it was enough to give the photos a noticeable 3-D effect, which I quite like. I will restrict the photos I show here to the ones I shot at f/8.
The two tripods I used were a set of Bogen 3021 legs with a large, no-name ball head, and a Majestic Model H-120 with a top plate the measures 5-3/4" x 7". It has a crank that operates a very smooth tilt function.
Pentax 67, 300mm f/4 @ f/8, 1/30 second. T-Max 100 developed in D-76. Bogen 3021 legs, no-name ball head.
Ditto above, with MLU engaged.
Pentax 67, 300mm f/4 @ f/8, 1/30 second. T-Max 100 developed in D-76. Majestic H-120 tripod.
Ditto above, with MLU engaged.
Results: I found the images using both the Bogen and the Majestic to be quite acceptable. There was the smallest amount of blur with some twigs in some of the photos, but I can't be certain it wasn't the wind causing the blur, and it wasn't consistent. There was no appreciable difference between the shots with the Bogen and those with the much more massive Majestic.There was also little, if any, difference between shots where the mirror was locked up and where it was free to slap happily away.
The exposures could have been better. I used the Pentax's internal meter. I should have at least double-checked it with one of my hand-held meters.
I did a google search on my no-name ball head, hoping to find a brand name, but wasn't successful. However, in the process, I came across a listing for an economical tripod (with ball head) that I thought I'd mention here. It's a Vanguard Alta Pro 263AB 100. It is one of those hard-to-find models that has a pivoting center post, which can be very handy if one is after closeups of small flora and/or fauna. Supposedly, it will support up to 15.4 lb. Here's a link to it:
https://www.bhphotovideo.com/c/prod...rd_ALTA_PRO_263AB_100_Alta_Pro_263AB_100.html