Mark - I know a couple of members at Loch Lomond who were able to help arrange a round for us.
As far as playing from the tips, I have found that simply asking the pro or secretary is sufficient. On our last trip to England / Scotland in August, we played Alwoodley, Birkdale, West Lancs, Lytham, Formby, Hillside, Cruden Bay, Peterhead, Fraserburgh, Lossiemouth, Boat of Garten, Dornoch, Brora, Tain, Golspie and Skibo. The only two clubs that refused to let us play from the medal tees were Boat of Garten and Birkdale. We didn't ask at Birkdale (it was so stuffy we figured what the answer would be) and Boat of Garten required a vote of the members or something. The other clubs, when we showed them that we were single digit handicaps, were happy to let us play from the backs.
In general, I have found that the farther north you go in Scotland, the easier it is to play from the medal tees. On my first visit to Cruden, I walked up to the white tee on the first hole and my caddy started to make fun of me. He asked if I didn't think I could handle it from all the way back! So, back I went and away we went!
BTW - One of your books (I can't remember the name and I'm not at home to look) was very helpful in planning the England portion our trip. Thanks!